Chapter 2b CNS Gross Anatomy

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Chapter 2b CNS Gross Anatomy

• Chris Rorden
• University of South Carolina
• Norman J. Arnold School of Public Health
• Department of Communication Sciences and
  Disorders
• University of South Carolina

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Brain Sub-Divisions

• Telencephalon Cortex, Limbic system, basal
  ganglia, olfactory bulb
• Diencephalon
• Thalamus, Hypothalamus
• Mesencephalon
• Colliculi,
• Rhombencephalon
• Pons, Cerebellum, Medulla
• Spinal 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 MRI
• Bilateral 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

• Pons
• Medulla Oblongata
• Functions Automatic Control Systems

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Ventral Brainstem

• Mamillary Bodies
• Medial Sulcus
• Ventral Median Fissure
• Pyramidal Tract
• Pyramidal Decussation
• Where signals cross
• Ventral 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 Body
Brachium Superior Colliculus Inferior Colliculus
Colliculus Superior Inferior Trochlear Nerve
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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
Basis Pedunculi
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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 Tegmentum
• Ventral Pyramidal Tract
• Reticular Formation
• Cardiac Center
• Vasomotor Center
• Respiratory Center

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Cerebellum

• Modifies Cortical Activity
• Distinctive Appearance
• Gyri called Folia
• Two Hemispheres
• Three Lobes
• Anterior
• Posterior
• Flocculonodular

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Cerebellum
Posterior lobe

• Rostral view
• (birds eye)

Anterior lobe
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Cerebellum

• Caudal view (from the feet)

Posterior lobe
Anterior lobe
Flocculus
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Cerebellum

• Anterior view

Flocculus
Nodulus
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Cerebellum

• Midsagittal slice

Nodulus
Flocculus