1 cerebellum kiranmayi s.. 3 cerebellum 50% of brain’s neurons, 10% of volume can change movements...
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1
Cerebellum
Kiranmayi S
3
Cerebellum
50 of brainrsquos neurons 10 of volumeCan change movements as necessary
ndash EG Walking or talking
Does not reach conscious awarenessMuscle synergy or coordination monitoredImportant in running speaking - all fluid
movements
THE CEREBELLUM AND BASAL GANGLIA COORDINATE MOVEMENTS
THE CEREBELLUM IS INVOLVED IN PLANNING COORDINATION AND POSTURE
ANTERIOR AND POSTERIOR LOBES INVOLVED IN LIMB MOVEMENT
FLOCCULONODULAR LOBE IS INVOLVED IN EQUILIBRIUM AND POSTURE
5
Function of Cerebellum
Error Control Device - Monitor Quality Controlndash Monitors outputs to muscles from motor cortex and
sensory signals from receptorsndash Compares the efferent project plan with execution
at motor action sitendash Considers related factors and makes adjustments
Evolution
3 main stages based on the complexity of movement
Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and
learned movement
6
7
tentorium cerebelli
tent of the cerebellum dura mater that
separates the cerebellum from the inferior portion of the occipital lobes
8
Posterior Cranial Fossa
Fossa is a depression or cavity in the bone
Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa
9
Cerebellar Anatomy
Located dorsal to pons and medulla
In posterior fossa under tentorium cerebelli
Lobesndash Floccular Nodular(small
fluffy mass)ndash Anteriorndash Posterior
Seen from feet
Posterior lobe (I)
Anterior lobe (H)
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
3
Cerebellum
50 of brainrsquos neurons 10 of volumeCan change movements as necessary
ndash EG Walking or talking
Does not reach conscious awarenessMuscle synergy or coordination monitoredImportant in running speaking - all fluid
movements
THE CEREBELLUM AND BASAL GANGLIA COORDINATE MOVEMENTS
THE CEREBELLUM IS INVOLVED IN PLANNING COORDINATION AND POSTURE
ANTERIOR AND POSTERIOR LOBES INVOLVED IN LIMB MOVEMENT
FLOCCULONODULAR LOBE IS INVOLVED IN EQUILIBRIUM AND POSTURE
5
Function of Cerebellum
Error Control Device - Monitor Quality Controlndash Monitors outputs to muscles from motor cortex and
sensory signals from receptorsndash Compares the efferent project plan with execution
at motor action sitendash Considers related factors and makes adjustments
Evolution
3 main stages based on the complexity of movement
Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and
learned movement
6
7
tentorium cerebelli
tent of the cerebellum dura mater that
separates the cerebellum from the inferior portion of the occipital lobes
8
Posterior Cranial Fossa
Fossa is a depression or cavity in the bone
Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa
9
Cerebellar Anatomy
Located dorsal to pons and medulla
In posterior fossa under tentorium cerebelli
Lobesndash Floccular Nodular(small
fluffy mass)ndash Anteriorndash Posterior
Seen from feet
Posterior lobe (I)
Anterior lobe (H)
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
THE CEREBELLUM AND BASAL GANGLIA COORDINATE MOVEMENTS
THE CEREBELLUM IS INVOLVED IN PLANNING COORDINATION AND POSTURE
ANTERIOR AND POSTERIOR LOBES INVOLVED IN LIMB MOVEMENT
FLOCCULONODULAR LOBE IS INVOLVED IN EQUILIBRIUM AND POSTURE
5
Function of Cerebellum
Error Control Device - Monitor Quality Controlndash Monitors outputs to muscles from motor cortex and
sensory signals from receptorsndash Compares the efferent project plan with execution
at motor action sitendash Considers related factors and makes adjustments
Evolution
3 main stages based on the complexity of movement
Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and
learned movement
6
7
tentorium cerebelli
tent of the cerebellum dura mater that
separates the cerebellum from the inferior portion of the occipital lobes
8
Posterior Cranial Fossa
Fossa is a depression or cavity in the bone
Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa
9
Cerebellar Anatomy
Located dorsal to pons and medulla
In posterior fossa under tentorium cerebelli
Lobesndash Floccular Nodular(small
fluffy mass)ndash Anteriorndash Posterior
Seen from feet
Posterior lobe (I)
Anterior lobe (H)
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
5
Function of Cerebellum
Error Control Device - Monitor Quality Controlndash Monitors outputs to muscles from motor cortex and
sensory signals from receptorsndash Compares the efferent project plan with execution
at motor action sitendash Considers related factors and makes adjustments
Evolution
3 main stages based on the complexity of movement
Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and
learned movement
6
7
tentorium cerebelli
tent of the cerebellum dura mater that
separates the cerebellum from the inferior portion of the occipital lobes
8
Posterior Cranial Fossa
Fossa is a depression or cavity in the bone
Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa
9
Cerebellar Anatomy
Located dorsal to pons and medulla
In posterior fossa under tentorium cerebelli
Lobesndash Floccular Nodular(small
fluffy mass)ndash Anteriorndash Posterior
Seen from feet
Posterior lobe (I)
Anterior lobe (H)
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Evolution
3 main stages based on the complexity of movement
Archecerebellum ndash balancePaleocerebellum ndash posture locomotionNeocerebellum ndash programming skilled and
learned movement
6
7
tentorium cerebelli
tent of the cerebellum dura mater that
separates the cerebellum from the inferior portion of the occipital lobes
8
Posterior Cranial Fossa
Fossa is a depression or cavity in the bone
Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa
9
Cerebellar Anatomy
Located dorsal to pons and medulla
In posterior fossa under tentorium cerebelli
Lobesndash Floccular Nodular(small
fluffy mass)ndash Anteriorndash Posterior
Seen from feet
Posterior lobe (I)
Anterior lobe (H)
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
7
tentorium cerebelli
tent of the cerebellum dura mater that
separates the cerebellum from the inferior portion of the occipital lobes
8
Posterior Cranial Fossa
Fossa is a depression or cavity in the bone
Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa
9
Cerebellar Anatomy
Located dorsal to pons and medulla
In posterior fossa under tentorium cerebelli
Lobesndash Floccular Nodular(small
fluffy mass)ndash Anteriorndash Posterior
Seen from feet
Posterior lobe (I)
Anterior lobe (H)
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
8
Posterior Cranial Fossa
Fossa is a depression or cavity in the bone
Cerebellum pons and medulla oblongata sit in the Posterior cranial fossa
9
Cerebellar Anatomy
Located dorsal to pons and medulla
In posterior fossa under tentorium cerebelli
Lobesndash Floccular Nodular(small
fluffy mass)ndash Anteriorndash Posterior
Seen from feet
Posterior lobe (I)
Anterior lobe (H)
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
9
Cerebellar Anatomy
Located dorsal to pons and medulla
In posterior fossa under tentorium cerebelli
Lobesndash Floccular Nodular(small
fluffy mass)ndash Anteriorndash Posterior
Seen from feet
Posterior lobe (I)
Anterior lobe (H)
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
11
Flattened Cerebellum
Longitudinally separated into hemispheres and corticesndash Median (Vermal)
Vermis=worm
ndash Paramedian (Paravermal
ndash Lateral
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
12
Cerebellum
Median Paramedian PrimaryFissure
PosteriorSuperiorFissure
HorizontalFissure
Posterolateral Fissure
Prepyramidal Fissure
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
13
Transverse Cerebellar Regions
1 Floccular nodular lobe (Archicerebellum )ndash Oldest related to vestibular part of VIIIndash Regulates equilibrium through vestibulospinal tract
2 Anterior lobe (Paleocerebellum)ndash Rostral to Primary Fissurendash General Sensory Receptorsndash Concerned with muscle tone and walking
3 Posterior lobe (Neocerebellum)ndash Newest and Largest Receives afferent projections from contralateral
sensorimotor cortexndash Projects to contralateral motor cortexndash Functions in coordination of fine and skilled movements
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
14
Longitudinal Cerebellar Regions
Vermisndash Contributes to body posture
Paravermal regionndash Regulates movements of ipsilateral extremities
(eg walking)
Lateral Zonendash Regulates skilled movements of ipsilateral
extremity (eg tying your shoe)
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
15
Cerebellar Connection
Three Peduncles1 Inferior ndash afferent mediate sensorimotor input to the
cerebellum2 Middle ndash afferent same as above3 Superior ndash efferent transmit output from the cerebellum to
the brainstem and on to the thalamus motor cortex and spinal cord
Varied afferents to Cerebellum ndash spinal cordndash brainstem ndash motor cortex
AfferenetEfferent Ratio = 401ndash For each going from cerebellum to body 40 coming in
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Cerebellar Nuclei
16
Dentate NucleusNeocerebellum
Paleocerebellum Globose amp emboliform nuclei
Archecerebellum
Fastigeal Nucleus
Vestibular Nucleus
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
17
Cerebellar Nuclei (Nuclei = deep cluster of neurons)
Dentate nucleusndash Largest communicates through cerebellar peduncle ndash Carries information important for coordination of limb
movements (along with the motor cortex and basal ganglia)
Emboliform nucleus (medial side of the nucleus dentatus)ndash Regulates movements of ipsilateral extremity
Globose nucleusndash Regulates movements of ipsilateral extremity
Fastigial nucleusndash Regulates body posturendash Is related to the flocculo nodular lobe
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
18
Dentate Nucleus
Pons
PontineProjections
DentateNucleus
SuperiorCerebellarPeduncle
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
19
Somatotopic Organization
Tactile informationndash Ipsilateral anterior lobule ndash Bilateral paramedian lobulesndash Cerebral Cortex and
Cerebellum have similar representations
Motor representationndash Same area as sensory
mappingndash May have auditory and visual
processing
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
20
Afferent Pathways (Inferior)
Vestibulocerebellar Tractndash Info From Semicircular Canals Through Inferior
Pedunclendash Maintains Upright Posture
Dorsal Spinocerebellar Tractndash Info From Reticular Nuclei (involved in regulation
of sleep respiration heartbeat etc)ndash Unconscious Proprioception From Muscle
Spindles Golgi Tendons and Tactile Receptors
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
21
Afferent and Efferent Projections
Superior CerebellarPeduncle
Red nucleus
Thalamus
Middle CerebellarPeduncle (pontocerebellar fibers)
Inferior Cerebellar Nucleus(olivocerebellar fibers)
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
22
Afferent Pathways (Middle)
Info From Pontine Nuclei From Opposite Cerebral Cortex Visual and Auditory Inputs
To Opposite Cerebellar Hemisphere
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Afferent Connections amp Functions
23
Equilibration ndash vestibular nuclei to archecerebellum through VIII nerve
Subconscious Proprioception ndash anterior lobe is ipsilateralndash Feet ndash anterior upper limbs posterior head in
located posteriorly in the superior vermis
Motor Control Circuits ndash coordinates muscle groups smoothes muscle action adjusts muscle tone so that force and its direction and extent are appropriate and accurate
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
24
Efferent Pathways
Cerebral cortex ndash dentato-rubro-thalamic route to the motor cortex
Red nucleus ndash limb movementsReticular formation ndash muscle toneVestibular nuclei ndash equilibrium
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
25
Cerebellar Cortex
Structured in Three Parallel Layersndash Molecularndash Purkinje
Connecting Surface and Deep Cerebellar NucleiSource of All Efferent FibersCerebellar Cortex
ndash GranularHave Mossy Fiber Axons to Purkinje Axons
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
CELL TYPES AND CIRCUITS IN THE CEREBELLUM
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Cerebellar Cortex
Molecular layer ndash superficial has few cells and many fibers run parallel to the folia and form granular cells of the deep layer ndash Satellite cells and Basket cell
Purkinje cells ndash very large Golgi type I neurons ndash Large flask shaped cell bodies with profusely
branched dendrites (400 000 synapses)
Granular cells- vast numbers of small neurons with axons ascending into the molecular layer
27
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES
TWO INPUTS CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS
OUTPUT VARIES ACORDING TO INPUT CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
CEREBELLAR LESIONS
IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN
COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE
ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS
PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
30
Clinical Considerations
Signs of Dysfunctionndash Impaired Muscle Synergyndash Reduced Muscle Tonendash Evident in Skilled Tasksndash Ataxia
Lack of Order and Coordination in ActivitiesSlow Movement (Bradykinesia)Mild Muscular Weakness (Asthenia)AsynergiaSpeech difficulties (Ataxic Dysarthria)
ndash affects respiration phonation resonance and articulation but most pronounced in articulation and prosody
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Overview of Hypothalamus
Is very smallWeighs only about 4 gramsBrain=1400 gramsContains a variety of specialized structures
31
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Functions of Hypothalamus
Autonomic nervous system regulationHormone productionEndocrine regulationCircadian rhythm regulationLimbic system interactionVarious
ndash Temperature regulationndash Feeding
32
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
33
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Regulates Mechanism by
Receiving sensory information from all areas of the body
Comparing sensory information with biological set points
Adjusting the system to restore the body balance when deviations from biological set points occur
Example Set pointsndash Blood sugar Hormone levels Temperature
Sodium34
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Autonomic nervous system regulationInfluences PSNS through projections to brainstem
PSNS nuclei
Posterior area influences SNS through projections to the lateral gray horn
35
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Hormone ProductionMagnocellular regions of the supraoptic and
paraventricular nuclei produce oxytocin and vassopressin (ADH)
Transported via axonal transport systems (hypothalamohypophysial tract) to neurohypophysis1048700
Released in circulationDamage to supraoptic n diabetes insipidusrArr
36
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Hormone Production
ndash Stimulating or inhibiting hormones are transported via the tuberoinfundibular tract and released in to the pituitary portal system and ultimately to the adenohypophysis
37
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
Cercadian rhythm regulation
ndash Input from retina to suprachiasmatic nucleus is then sent through poorly defined projections to the pineal gland
38
Temperaturendash Posterior n conserves heatndash Anterior n dissipates heatndash Fever starts ndash sweatingndash Fever ends ndash chills
Feedingndash Lateral n induces eatingndash Ventromedial n inhibits eating
39
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