Cranial Fossa
 Use the autopsy saw to cut the calvaria in a flat cut away from the neurocranium.
 Carefully pry the calvaria from the surface of the brain leaving the dura mater
attached to the brain as much as possible.
 Use a long sectioning knife to cut the brain along the mid-sagittal plane.
 Use a scapel to cut the tentorium free from its attachement along the skull.
 Cut all exposed cranial nerves as long as possible
 Carefully pry the one half of the cerebral hemisphere from the anterior portion of
the skull, cutting cranial nerves and blood vessels as you go.
 Once the cerebellum is freed reach as deeply as possible to sever the medulla
from the spinal cord.
 Repeat with other half.
 Examine the inside of the skull and note sella turcica covered by sellar
diaphragm.
 Cut the diaphragm to expose and extract the pituitary gland.
Interior of Skull and Brain
Cranial Fossa, greater and lesser wing of sphenoid, crista galli, sella turcica (hypophyseal fossa,
anterior and posterior clinoid processes, chiasmatic groove, dorsum sella), transverse sinus
depression, petrous portion of temporal
Openings: foramen magnum, foramen ovale, foramen rotundum, hypoglossal canal, internal
auditory meatus, foramen spinosum, jugular foramen, cribiform foramina, optic canal, carotid
canal, foramen lacerum
Brain and Meninges
1. Meninges:
a. dura mater (two layers: an outer rough layer that adheres to the skull and an inner
smooth lining that rests against the arachnoid (distinguishable only where they
separate to allow venous blood flow through venous sinuses); understand meningeal
blood flow, venous sinuses, arachnoid granulations and the flow of CSF and blood
drainage
-note space between dura and arachnoid (subdural space) is potential space normally
devoid of fluid –in trauma (like concussions) may fill with blood, same is true for
epidural space which normally only contains the meningeal arteries
-three meningeal dural folds help to suspend brain within cranium (tentorium cerebelli,
falx cerebri, and falx cerebelli)
b. arachnoid –membrane with fibrous extensions that create the subarachnoid space
which is filled with CSF; the subarachnoid space directly connects via three brain
foramen to the 4th ventricle of the brain where CSF forms
c. pia mater –thin, transparent covering of brain
Brain
Gross External features
1. Cerebrum divided in half by longitudinal cerebral fissure into the:
cerebral hemispheres –divided into lobes: frontal, parietal, occipital, temporal with two
large fissures: Lateral (Sylvius) and Central (Rolando) sulci
-note other gyri and sulci
i. Cerebellum –sulci and folia, right and left cerebellar hemispheres and the
vermis
ii. Thalamus –hypothalmus, optic chiasma, infundibulum, pituitary gland
iii. Midbrain –superior and inferior colliculi, pineal gland, mammillary body
iv. Pons
v. Medulla oblongata
Sagittal Features of Brain
a. Distinguish features from above list
b. Corpus callosum, intermediate mass, fornix, septum pellucidum, choroid plexus,
arbor vitae, the 4 ventricles, and the cerebral aqueduct
Blood Supply
c. Circle of Willis, internal carotid artery vertebral arteries, posterior
communicating, anterior communicating, basilar artery and posterior, middle
and anterior cerebral arteries; see x-rays too
d. Study Blood Supply from book
Cranial Nerves 12 know by name and number –from model and book diagrams