The Skull

Front 1

Anterior Cranial Fossa Boundaries

Back 1

Ant. and Lat. borders: Frontal Bone
Post.: lesser wings of sphenoid bone
Floor: orbital plates of frontal bone, cribiform plate of ethmoid, lesser wings and ant. part of sphenoid body

Front 2

Anterior Cranial Fossa Contents

Back 2

Frontal: foramen cecum

Ethmoid Bone: Cribiform Plate, Crista galli, and Ant./Post. ehtmoidal foramina

Front 3

Frontal Bone- contents of ant. cranial fossa

Back 3

foramen cecum: nasal emissary veins go through here. they are the veins of nasal cavity to superior sagittal sinus.

Front 4

Cribiform Plate of Ethmoid Bone-Contents of Anterior cranial fossa

Back 4

provides bed for olfactory bulbs, foramina for olfactory nerve fibers.

Front 5

Crista galli-Contents of Anterior cranial fossa

Back 5

AKA cock's comb. attachment site of falx cerebri, the membrane that stabilizes the position of the brain.

Front 6

Anterior and Posterior ethmoidal foramina-contents of anterior cranial fossa

Back 6

vessels and nerves of Ant. and Post. ethmoidal foramina go here.

Front 7

Middle Cranial Fossa Boundaries

Back 7

Ant: post. borders of lesser wings of sphenoid bone
Post: petrous ridge of temporal bone & dorsum sellae of sphenoid bone
Floor: greater wings of sphenoid bones and squamous and petrous parts of temporal bone.
Lateral: squamous part of temporal bones

Front 8

Middle cranial fossa contents: Sphenoid

Back 8

schismatic groove, optic canal, superior orbital fissure, sella turcica, carotid canal and groove, foramina

Front 9

Schismatic groove of sphenoid bone

Back 9

optic chiasm

Front 10

Optic canal of sphenoid bone

Back 10

optic nerve and opthalmic artery

Front 11

Superior orbital fissure of sphenoid bone

Back 11

Between greater and lesser wings of sphenoid bone. Following nerves pass through here: Oculomotor (III), Trochlear (IV), Opthalmic division of Trigeminal (VI), Abducens (VI) sympathetic fibers from internal carotid plexus

Front 12

Sella Turcica of Sphenoid bone

Back 12

turkish saddle-fossa for pituitary
Dorsum sellae
Ant/Post clinoid processes. Attachment sites for diaphragm sellae- diaphragm over pituitary fossa-stalk of pituitary passes through here.

Front 13

Carotid canal and groove of sphenoid bone

Back 13

for internal carotid arter, sympathetic nerve and lymphatics

Front 14

Foramina of sphenoid bone

Back 14

Rotundum-maxillary division of Trigeminal (V2)
Ovale-mandibular division of Trigeminal (V3) & accessory meningeal artery
Spinosum- middle meningial artery and vein, meningeal branch of mandibular nerve (next to spines)
Lacerum-b/w sphenoid, temporal, and occipital bones. filled with fibrocartliage, internal carotid artery passes across, NOT THROUGH.

Front 15

Rotundum Foramina

Back 15

maxillary division of Trigeminal V(2)

Front 16

Ovale Foramina

Back 16

mandivular division of Trigeminal (V3) and accessory meningeal artery

Front 17

Spinosum Foramina

Back 17

middle meningeal artery and vein, meningeal branch of mandibular nerve.

Front 18

Lacerum Foramina

Back 18

between sphenoid, temporal, and occipital bones. Filled with fibrocartilage. Internal carotid artery passes across, NOT THROUGH

Front 19

Boundaries Posterior Cranial Fossa

Back 19

Ant: petrous ridge of temporal bone and dorsum sellae of sphenoid bone
Walls: petrous part of temporal bone and occipital bone (which also forms floor)

Front 20

Contents of Posterior Cranial Fossa

Back 20

Temporal Bone-internal acoustic meatus, jugular foramen, and groove for sigmoid sinus
Occipital Bone- internal occipital protuberance, foramen magnum, hypoglossal cana, condyloid foramen, mastoid foramen

Front 21

Internal Acoustic Meatus of Temporal Bone

Back 21

Facial Nerve (VII), Vestibulocochlear (VIII), and labyrinthine artery.
Facial Nerve (VII) EXITS through the stylomastoid foramen.
Vestibulcochlear (VIII) terminates in the inner ear.

Front 22

Jugular Foramen of Temporal Bone

Back 22

Glossopharyngel Nerve (IX), Vagus Nerve (X), Accessory Nerve (XI)
inferior petrosal and sigmoid sinuses drain into internal jugular vein
posterior meningeal artery

Front 23

Internal Occipital protuberance of Occipital Bone

Back 23

Attachment site for falx cerebri

Front 24

Foramen Magnum of Occipital Bone

Back 24

spinal cord, spinal roots of accessory nerve (XI), vertebral artery, anterior and posterior spinal arteries, dural veins

Front 25

Hypoglossal Canal of Occipital Bone

Back 25

Hypoglossal Nerve (XII)

Front 26

Condyloid Foramen of Occipital Bone

Back 26

emissary vein

Front 27

Mastoid Foramen of Occipital Bone

Back 27

mastoid emissary vein

Front 28

Grooves for Occipital Bone

Back 28

transverse, superior sagittal, and occipital sinuses