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Nervous system
BRAIN
Questions
Structure of brain
Brainstem
Hindbrain: medulla oblongata, pons, cerebellum
Reticular formation
Midbrain: superior and inferior colliculus
Diencephalon: thalamus, hypothalamus
Subcortical nuclei (Basal nuclei)
Limbic system
Ventricular system
Cranial nerve
BRAIN
unites structures,
which control vital
activity of an
integrated organism
and the higher
nervous formations,
which coordinate the
vital organisms`
processes, provide
adaptive behavior and
mental activity
Brain
Hindbrain
Medulla
oblongata
Pons
Cerebellum
(little brain)
Midbrain
Hillocks (superior
and inferior)
Legs.
Diencephalon
Thalamus
Hypothalamus
Forebrain
•Cerebral
hemisphere;
•Basal
ganglia;
•Limbic
system
(visceral
brain).
Brainstem
Medulla oblongata
Pons
Midbrain
Diencephalon (partially)
The hindbrain is composed of the medulla, the pons, and the cerebellum. The medulla lies next to the spinal cord and controls functions outside conscious
control, such as breathing and blood flow. In other words, the medulla controls essential functions. The pons affects activities such as sleeping, waking, and dreaming. The cerebellum controls balance and coordination of movement.
Damage to the cerebellum impairs fine motor skills, so a person with an injury in this area would have trouble playing the guitar or typing a term paper.
The Midbrain The midbrain is the part of the brain that lies between the hindbrain and the forebrain. The midbrain helps us to locate events in space. It also contains a
system of neurons that releases the neurotransmitter dopamine. The reticular formation runs through the hindbrain and the midbrain and is involved in sleep
and wakefulness, pain perception, breathing, and muscle reflexes. The Forebrain
The biggest and most complex part of the brain is the forebrain, which includes the thalamus, the hypothalamus, the limbic system, and the cerebrum.
ThalamusThe thalamus is a sensory way station. All sensory information except smell-
related data must go through the thalamus on the way to the cerebrum. Hypothalamus
The hypothalamus lies under the thalamus and helps to control the pituitary gland and the autonomic nervous system. The hypothalamus plays an important role in regulating body temperature and biological drives such as hunger, thirst,
sex, and aggression.
Internal structure of a brain
Brainstem
Довгастий мозок
Brainstem
White and grey matters
Grey matter
(In the form of nuclei)
Cortex of Subcortical
Cerebellum nuclei
Cortex of the
big hemispheres
White matter
Conduction tracts
HINDBRAIN
The hind brain is mainly a
continuation of the spinal cord and contains all the ascending and
descending fibers connecting the brain
and spinal cord.
The medulla (as known as the medulla
oblongata) is located at the base of the brain stem
and controls many of the mechanisms necessary
for life, such as heartbeat, blood pressure and
breathing. White and gray substance aren't parted
Clumps of nervous cells are nuclei of cranial
nerves:
XII – Hypoglossal - tongue movement
XI – Accessory - neck and shoulder muscles
X – Vagus - swallowing, taste
IX – Glossopharyngeal - taste, swallowing
VIII – Acoustic (Vestibulocochlear Nerve ) -
hearing, balance
Function of medulla oblongata
Medulla (oblongata)
Vital functions: breathing, heart
rate, digestion
Protective reflexes - vomiting,
coughing, sneezing, elimination of
tears, a winking
Reflexes of alimentary
behavior: digestive juice
elimination, chewing, swallowing,
a suction;
Reflexes of a postur`s changes
- a muscles` tonus
Conduction
Binds a spinal cord to brain
departments
Connections through the
cranial nerves (sensation
and motor nerves for
head) and
parasympathetic nervous
system
Vestibular reflexes:
Static – posture maintenance and equilibriums
of a body at different static positions in a
space
Statokinetic – posture maintenance at change
of rate of movement of a body in space
Vegetative reflexes – locomotor and
secretory activity of an internal at vagus
excitation.
Functions of medulla oblongata
Importance
Maintenance of a constancy of structure of internal medium – a homeostasis (activity of vital centers)
Association of segments of a spinal cord
Regulation of work of a spinal cord
Realization of difficult forms of adaptive reactions of an organism to environment
Medulla oblongata and pons
Reticular formation (RF) – special formation – a net of
nervous fibers in brainstem and hindbrain
Functions:
Maintenance of interaction of ascending and
descending pathways of a brain
Coordination of an organism functions.
Reticular formation of brainstem
System of nervous cells of the various form and the sizes
with a lot of processes which intertwine and form a lot
of contacts
Functions of RF
Specifies
Breath regulation
Regulation of hard
activity
Regulation of a
vascular tonus etc.
Unspecifies
Regulation of
level of functional
activity of brain
departments
(activation or
inhibition)
Regulation of breath`s
center (pneumotaxic
center influences
depth and frequency
of breath)
The vascular center
The respiratory center
Activation of neurons of a
spinal cord
Functions
RF of medulla oblongata
Pons (the "bridge")
Structure
Cranial nerves:
V - Trigeminal
VI – Abducent
VII - Facial
VIII – Acoustic(VestibulocochlearNerve )
Many nerves cross over from one
side of the body to the other
Contains (within the medulla and
pons) the reticular formation and
raphe system
Ascending reticular
formation: sends output to
cerebral cortex and controls
arousal and attention
functions
raphe system: axons to the
forebrain
increasing/decreasing
readiness to respond to stimuli
Pons
Pons connects medulla oblongata to mesencephalon peduncles
Functios
Control ConductionVestibular reflexes, which Ascending and descending nervous ways -
regulate a tonus of muscles, fibers which bridge cerebellum
including mimic hemispheres themselves and a cortex
of the big brain
Cranial nerves:
VII – Facial - taste, facial expressions
VI – Abducent - eye movements
V – Trigeminal - facial sensations, chewing
Cerebellum
Cerebellum
Cerebellum bonds with CNS
Cerebellar peduncle
Inferior with medulla Superior with midbrain
oblongata and spinal cord and hypothalamus
Middle with
pons and across it
with an motor zone of a cortex
Function of cerebellum
Coordination of muscle slow movements
Control of a body position
Fine motor skills
Maintaining balance, posture, and equilibrium
Muscle tone control: equilibrium, forces of
muscular contraction
Vegetative functions:
Influence on the work of cardiovascular, respiratory,
digestive and other systems
Influence on a metabolism
Midbrain
Midbrain (structure)
Peduncles
Substantia Red
nigra nucleus
Mesencephalic
tegmentum
(Quadrigeminal plate)
Superior Inferior
colliculus colliculus
Functions of midbrain (the center of
regulation of support of normal position of a
body)Quadrigeminal plate – the organization of rough visual and
acoustical reflexes on visual and acoustical irritation
Superior colliculus – the primary visual centers,realization of visual reflex reactionsMovement of head
Movement of eyes
Change of a lumen of a pupil
Accommodation change
Inferior colliculus – the primary acoustical centers
Movement of head
Movement of auricle
Tension of the tympanic membrane, auditory ossicles
Red nucleus – regulation of a muscular tonus of the
planned adjustable movement and pose maintenance
– inhibition of a motor activity of a spinal cord
Substantia nigra (Contains melanin)
Regulation of certificates of chewing, swallowing
Maintenance of exact movements of fingers of arms
Regulation of plastic tonus
Cranial nerves
IV – Trochlear - eye movements
III – Oculomotor - eye movements, eyelid opening
DiencephalonThe center of sensory, movement and vegetative reactions
of an organism
Structure of diencephalon
Thalamus Hypotalamus
(optic thalamus) (subthalamic
Cranial nerve region)
II Optic - vision
Structure of Brain
Тhаlаmus
The highest subcortical center of the afferent
information from all external and internal receptors
which perceive irritation except the olfactory.
Grey matter consist of 40 nuclei
Classification of nuclei by character
of influence on a cerebrum
Specific
Process and transition
visual, movement,
tactile, gustatory
signals to definite
associative zones of a
cerebrum.
Nonspecifies
Excitation diffusively
propagates in
hemispheres. Creation
of the general activity
of a cerebrum for
consciousness
maintenance.
Kinds of specific nuclei
Switching - send the tactile, temperature,
painful, gustatory, acoustical, visual
information to a certain lobe of a cortex;
Associative – receive impulses from
switching and send to frontal, temporal area
of a cerebrum;
Impellent – switching of signals from a
cerebellum, basal a ganglion in a motor lobe
of a cerebrum.
Function of thalamus
Receive and estimation of the information from
sense organs;
Allocation and transfer to a cortex of the most
important information;
Regulation of emotional behavior;
The center of painful sensitivity;
Coordination of difficult movement functions (a
suction, chewing, swallowing, laughter) with
vegetative processes.
Hypothalamus
• The center of regulation of vegetative functions
which provide homeostasis support, regulation
of functions of vegetative, endocrine and
somatic systems.
• Grey matter consist of 32 (50 pars) nuclei
Function of hypothalamus The center of sympathetic and parasympathetic nervous
systems (forward and back nuclei);
Regulation of endocrine system;
Thermoregulation (back nuclei);
The centers of saturation, hunger, thirst;
The center of regulation of a dream, wakefulness;
Synthesis of hormones: a vasopressin, oxytocin
(supraoptic nucleus), liberins, statins
Metabolism regulation (middle nucleus);
Synthesis peptides – enkephalins, endorphines;
Formation of motivations together with limbic system;
Correcting of deviations of a homeostasis by means of
nervous and humoral mechanisms
Subcortical nuclei (Basal nuclei)
Are located in the middle of the big
hemispheres, between front parts and an
diencephalon
Subcortical Brain Structures
(Basal nuclei)
Basal nuclei
Globus pallidus Nucleus caudatus Amygdala
The big neurons – the beginning Striated body (Alternating of
to axons which come to an end in white and gray substance)
nucleus of midbrain and diencephalon
(substantia nigra, red nucleus) Fine neurons and which axons
go to globus pallidus and substantia
Rough reactions nigra
Movements of extremities
Alimentary behavior Receives eisodic impulses from a
Difficult movements (walking, run) sensory lobe of a cortex,
Difficult mimic movements nonspecific nucleus of a
thalamus, substantia nigra
- through an diencephalon regulates vegetative functions and carries out instincts
- storing of difficult impellent programs
Striated body
Nucleus caudatus
Brake or exciting
influence on
subcortical
structures;
Muscle tonus.
Amygdala
The organization of
alimentary behavior;
- Meal search;
- Capture and
mastering.
Breath regulation,
sulivation.
Limbic systemIt is located in a depth of an average surface of hemispheres.
Limbic system
Functions:
Participation in regulation of vegetative functions(especially digestion);
Participation in regulation of congenital behavioralreactions;
Formation and regulation of emotions;
Formation and memory implication;
Homeostasis maintenance;
Control of reactions referred on self-preservation andkind conservation; Integration of the olfactoryinformation (I pair olfactory nerves);
Control of the referred behavior;
Coordination of vegetative and somatic reflexesaccording to an emotional condition (anger, pleasure,a sexual inclination, alarm).
Ventricular systemThe brain is not a solid organ. There are
fluid-filled cavities within the brain called
ventricles. The ventricles are important in
providing nourishment to the brain. The
ventricular system produces and
processes cerebrospinal fluid – a clear,
watery substance that flows around the
brain and helps cushion and protect it.
Cranial nerve
LITERATURE
Anatomy and physiology. - The
McGraw−Hill, Companies, 2003