Produced by choroid plexus (modified ependymal cells) in ventricles

Circulates through ventricles and around brain

Protects and cushions brain

• Gyri are buldges/ridges and sulci are grooves
• Help increase SA, which increases # of nuerons, which increase cortical function

Named after the skull bones which cover them:

• Frontal lobe
• Parietal lobe
• Temporal lobe
• Occipital lobe
• Insula

Frontal and parietal- central sulcus

Frontal/parietal and temporal- lateral sulcus (sylvian fissure)

Anterograde degeneration (aka Wallerian degeneration)- segment distial to injury degenerates with a little bit of retrograde degeneration to site of injury

CNS- oligodendrocytes express inhibitory proteins -->no regeneration

PNS- Schwann cells guide fibers to targets

Bundle of axons that connect the left and right side of the brain

Decussation- crossing over in the shape of an X by nerve fibers in the CNS

Pryamidal- long axons which synapse in cortical or subcortical region

• Layers 3, 5, & 6
• Glutamanergic

Non-pyramidal

• Interneurons
• GABAergic

Granular = well developed layer 4

• Granular- primary sensory region (3, 1, 2) and prefrontal cortex (8, 9, 10)
• Agranular- primary motor region (4) and premotor (6)

Connect gyri of same hemisphere
Primarily axons of pyramidal neurons of layers 2 and 3

• Arcuate loop fibers- connect adjacent gyri
• Arcuate fasciculus
• Superior longitudinal fasciculus
• Uncinate fasciculus

• Connect homologous areas of each hemisphere
• Composed of axons of pyramidal neurons of layers 2 & 3

1. Corpus callosum

-Genu- connects anterior frontal lobes

-Body- connects posterior frontal lobes, parietal lobes, and superior temporal lobes

-Splenium- connects occipital lobes

2. Anterior Commisure

-Connects olfactory nuclei, amygdalas, and anterior temporal lobe

3. Posterior Commisure

-Connects pretectal nuclei (pupillary light reflex)

1. Neuralization (exclusively prenatally)
2. Migration (exclusively prenatally)
3. Arborization (begin prenatally into early adulthood)
4. Myelination of axons (begin prenatally into early adulthood)
5. Synapse formation and elimination (throughout life)

Dural septa and dural sinuses

Dural septa:

• Falx Cerebri- separates hemispheres of cerebrum
• Falx Cerebelli- separates hemispheres of cerebellum
• Tentorium cerebelli- separates cerebrum and cerebellum
• Tentorial notch- the opening in the tentorium cerebelli; surrounds midbrain

Drain venous blood of brain

4 Major Sinuses:

• Straight sinus
• Transverse sinus (L and R)
• Superior Sagittal sinus
• Sigmoid sinus
• Drains into internal jugular
• All others meet at confluence of sinuses