1. Endosteal (outer): adherent to outer surface of skull

2. meningeal (inner): adherent to endosteal, but 2 layers separate to enclose dural venous sinuses

-sheaths for CN when exiting skull

what artery:

• in dura
• branch of EXTERNAL CAROTID
• supplies cranial bones

compartments: supratentorial and subtentorial

communication between: terntorial incisure

1. superior sagittal

2. transverse

3. straight

4. occipital

• attaches to midline of tentorium
• septum of dura passing into longitudinal fissure
• limits side to side movement of cerebrum

• small septum of dura between 2 halves of cerebellum

• end point of venous drainage
• formed by 2 internal cerebral and 2 basal veins
• near pineal gland

1. ophthalmic

2. posterior communicating

3. ACA

4. MCA

5. anterior choroidal artery

• artery
• found near branching point of posterior communicating passing back near medial temporal lobe
• supplies: internal structures: basal ganglia, internal capsule, amygdala, hippocampus, choroid plexus of lateral ventricles

• right and left joined by anterior communicating artery
• supply medial aspect of each cerebral hemisphere
• supply pre and post central gyri

• lenticulo-straiate arteries
• supplies most lateral surface of frontal and parietal lobes & superolateral surface of temporal lobe
• strokes of MCA most common

• Lenticulo-striate arteries:

• supply caudate nucelus and internal capsule
• most lateral: artery of cerebral hemorrag because frequent involvement in hemorragic stroke

• terminal branches of basilar artery
• origin of internal carotid 25-40% of PCA
• supplies inferior temporal, occipital, and medial occipital lobe

• arises at entrance of vertebral artery into vertebral canal
• S-shaped bend as it crosses olive
• small posterior spinal arises from PICA (80%) near cerebellar peduncles
• supplies lateral medulla, choroid plexus of 4th ventricle, inferior cerebellum

• anterior portion of inferior cerebellum
• pons
• rostral medulla

1. superiofly: at foramen magnum where it is continuous with cranial dura

2.  inferiorly: to coccyx via dural covering of the filum terminale

3. laterally: to inververtebral foramen via dural sheaths of spinal roots

cervical: C3-T2-c6

lumbar: L1-S3-S1

spinal: S3-S5

vertebral: L1&L2

extends caudally from tip of of coneus and stops on dorsal surface of coccyx

has few nerve fibers

• formed by rootlets that arise from SC between dorsal and ventral roots of spinal levels C2

• fiber nervelets-ascend through cribiform plate of ethmoid bone to reach olfactory bulb
• nervelets: possesss characteristics of peripheral nerves but are surrounded by thin menginges

• outgrowth of the brain
• characteristics of CNS nerve fibers, not those of peripheral nerve
• covered in meninges, has own subarachnoid space connected with cerebral subarachnoid space
• veins draining in retina cross the subarachnoid space, so increases in ICP can compress and causes papilledma

• optic disc swelling due to increases in ICP
• veins draining retina cross the subarachnoid space, so increases in ICP can compress veins and cause papilledma

• extrinsic eye muscles, assisted by CN4 & CN6 as well
• intrinsic eye musculature controlling constriction of pupil and accomodation, and levator palpbrea superioris elevating upper eyelid
• emerges from midbrain in interpeduncular fossa and passing next between psterior cerebral and superior cerebellar arteries

• superior rectus
• inferior recuts
• medial rectus
• inferior oblique

• only CN arising from dorsal aspect of brain, curves around cerebral peduncle
• smallest CN
• fibers cross completely before leaving brain
• innervates: superior oblique

eyes: double vision, eye difts up

head: tile forward and tuck in chin to bring fields together

• arises from pons and can be identified emerging from middle cerebellar peduncle
• large sensory root and small separate motor root
• motor: lies more medial and anterior
• motor: mandibular divison for muscles of mastecation