CHI108 Week 2 - Central Nervous System in Relation to the Axial Skeleton class notes

W2 L2

Lecture 2 – Central nervous systems anatomy
& its relationship with the axial skeleton
Learning objectives

1. Recognise the central nervous systems relationship to the cranial fossa and vertebral canal.
2. Detail the gross anatomical features and structures associated with the central nervous systems
and spinal cord.
3. Review and define the role of the precentral and postcentral gyri.
4. Distinguish the gross neuroanatomy of the cerebrums and brainstems cranial nerves and their
specific actions.
5. Detail the meningeal coverings of the central nervous systems
6. Describe the ventricles and the choroid plexus’s role in cerebral spinal fluid (CSF) production.
7. Describe anatomical how spinal nerves are identified and how their numbered (identified) as they
exit the intervertebral foramen.
8. Summarise the anatomical aspects of a disc protrusion and the specific spinal nerve affected.

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Adult cranium: internal cranial base
The adult skull: an internal view of the cranial vault

• Anterior cranial fossa
o Shallowest of all 3 fossa
o Houses the frontal lobe
• Middle cranial fossa
o Inferior and posterior to 1
o Houses the temporal lobe and the superior part of the brain stem
• Posterior cranial fossa
o Most inferior and posterior of all the 3 fossa
o Houses the cerebellum and the inferior parts of the brain stem
Division of the cerebral hemispheres into lobes
The human brain

• The human brain is the central organ of the human nervous system
• The brain consists of the cerebrum, the brainstem and the cerebellum
• The cerebrum is the largest part of the human brain
• It is divided into two cerebral hemispheres, right and left
• The cerebral cortex is an outer layer of grey matter, covering the core of white matter
• The central nervous system consists of the two major structures; the brain and spinal cord
• The brain is encased in the skull while the spinal cord is continuous with the brain and lies
caudally to the brain, and is protected by the spinal canal
• From proximal to distal,
1. Cerebrum: cerebral hemispheres
2. Cerebellum
3. Brainstem
a. Midbrain
b. Pons
c. Medulla oblongata The human brain
4. Spinal cord

Ventricles of the brain

• The ventricles are a communicating network of cavities filled with cerebrospinal fluid
• Choroid plexus lines these ventricles and secretes CSF
• From superior to anterior,
○ Lateral ventricles (left and right)
▪ Frontal (anterior) horn
▪ Body (central part)
▪ Occipital (posterior) horn
▪ Temporal (inferior) horn
○ Interventricular foramen
○ Third ventricle
○ Cerebral aqueduct
○ Fourth ventricle
○ Central canal (within the spinal cord)

Structures of the brain

• The central sulcus separates the parietal lobe from the frontal lobe
• The corpus callosum is the largest white matter tract connecting the cerebral hemispheres
• The thalamus is deep within the cerebrum
o The thalamus is joined at inter-thalamic adhesion across the third ventricle
o The thalamus receives all sensory information (apart from smell) and sends it to the
cortex for integration and appropriate response (postcentral gyrus)
• The hypothalamus is distal to the thalamus and connects to the pituitary gland
o The hypothalamus is a portion of the brain that contains a number of small nuclei
with a variety of functions (regulation of certain metabolic processes)
o In turn the hypothalamus stimulates or inhibits the secretion of hormones from the
pituitary gland
• The pituitary gland
o The pituitary gland is located in the sella turcica of the sphenoid bone and connected


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