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Chapter 2b CNS Gross Anatomy
Chris RordenUniversity of South CarolinaNorman J. Arnold School of Public HealthDepartment of Communication Sciences and DisordersUniversity of South Carolina
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Brain Sub-Divisions
Telencephalon – Cortex, Limbic system, basal ganglia, olfactory bulb
DiencephalonThalamus, Hypothalamus
MesencephalonTegmentum, Red Nucleus,
ColliculiRhombencephalon
Pons, Cerebellum, MedullaSpinal Cord
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Diencephalon
Diencephalon = thalamus, hypothalamus, epithalamus, prethalamus or subthalamus and pretectum
Thalamus– Oval Mass of Neurons in
the Center of the Brain– Relays Sensorimotor
Information to the Cortex
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Thalamus
Poor contrast on MRI scans – hard to see.
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Thalamic Injury
T2-weighted MRIBilateral injury to parts of
thalamus
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Diencephalon
Hypothalamus– Body Heat, Water intake,
Hormone Production, Emotional Expression, Food Consumption and Reproduction
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Midbrain, Hindbrain
PonsMedulla OblongataFunctions: Automatic
Control Systems
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Ventral Brainstem
Mamillary BodiesMedial SulcusVentral Median FissurePyramidal TractPyramidal Decussation
– Where signals crossVentral lateral sulcus
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Midbrain Dorsal Structures
Superior and Inferior Colliculus – The ‘little hills’.– Superior colliculi – help
initiate eye movements, integrate visual, auditory and tactile information
– Inferior colliculi- audition Aka Corpora
Quadrigemina (four seeds)
Dorsal View of Brainstem
Pineal BodyBrachiumSuperiorColliculus
InferiorColliculus
ColliculusSuperior
Inferior
TrochlearNerve
Colliculi
Superior colliculi: eye movement control. Also maps touch and hearing onto vision
Inferior colliculi: pathway for auditory processing
Sagittal View
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Internal Structures of the Midbrain
Tegmentum Cerebral Aqueduct Red Nucleus Cranial nerve nuclei Reticular Formation Central Gray Area
Transverse Section of Rostral Midbrain
Tectum
Tegmentum
BasisPedunculi
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Internal structures of the pons
Tegmentum– Ascending and Descending Fibers– Medial Lemniscus
Basilar Pons– Cortical Descending Tracts– Pontine Nuclei – Pontocerebellar Fibers
Transverse Section of Mid Pons
Teg-mentum
Basilar
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Medulla Oblongata
Connects to Pontine Protrusion Caudal Portion Contains Pyramidal Decussation Where motor tracts cross over for control of contralateral
side of the body
Tegmentum
Pyramid
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Landmarks of Medulla
Ventral– Ventrolateral Sulcus– Pyramidal Tract– Lateral Corticospinal Motor Tract
Dorsal– Dorsal Median Sulcus– Dorsolateral Sulcus– Olivary Nucleus
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Internal Medulla
Dorsal TegmentumVentral Pyramidal TractReticular Formation
– Cardiac Center– Vasomotor Center– Respiratory Center
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Cerebellum
Modifies Cortical ActivityDistinctive Appearance
– Gyri called Folia– Two Hemispheres
Three Lobes– Anterior– Posterior– Flocculonodular
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CerebellumPosterior lobe
Anterior lobe
Rostral view– (bird’s eye)
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Cerebellum
Caudal view (from the feet)
Posterior lobe
Anterior lobe
Flocculus
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Cerebellum
Anterior view
Nodulus
Flocculus
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Cerebellum
Midsagittal slice
Flocculus
Nodulus