Anatomy Unit 23: Cranial Cavity

Front 1

Calvaria

Back 1

Skull cap composed of 3 bones. 2 Outer tables and dipole (spongy bone) in the middle.

Front 2

Dipole

Back 2

Spongy bone in middle of outer table of bones. Contains dipolic veins and marrow. Only develops later in childhood on bones not covered with thick, fleshy muscle.

Front 3

Emissary Veins

Back 3

Exit skull via emissary foramina. Connect dural venous sinus within cranium to veins external to it.

Front 4

Bones making up anterior cranial fossa

Back 4

Ethmoid, frontal, and lesser wing of spenoid.

Front 5

Bones making up middle cranial fossa and boundaries

Back 5

Sphenoid bone. separated from anterior by sphenoidal ridge. Separated from posterior by petrous ridge.

Front 6

Bones making up posterior cranial fossa

Back 6

temporal, sphenoid, and occipital bone.

Front 7

Layers of Dura Matter

Back 7

2 layers: Periosteal layer - Fused to bone and meningeal layer.
Meningeal layer - True layer of dura which forms double layer projection folds.

Front 8

4 Double layer projection folds

Back 8

Falx Cerebri
Falx cerebelli
Tentorium Cerebelli
Diaphragma Sellae

Front 9

Falx Cerebri

Back 9

Located in longitudinal fissure. Attaches anteriorly to crista galli of ethmoid bone.

Front 10

Falx Cerebelli

Back 10

Extends from the tentorium cerebelli downward to sperate the cerebellum into its hemispheres.

Front 11

Tentorium Cerebelli

Back 11

Separates occipital lobe of cerebrum form cerebellum. Attaches:
Laterally to petrous ridge of temporal bone.
Posteriorly along occipital bone at the transverse sinus.
Anteriorly at sides of anterior clinoid process.
Has tentorial notch which is an anterior concave margin is open and wraps around brainstem.

Front 12

Diaphragma Sellae

Back 12

Forms roof of sella turcica (which contains hypophyseal fossa for pituitary gland) of sphenoid bone. Infundibulum of hypothalamus pierces this dura.

Front 13

Internal jugular vein

Back 13

Formed in the jugular foramen by sigmoid sinus and inferior petrosal sinus.

Front 14

Superior Sagittal Sinus

Back 14

Along superior border of falx cerebri. Drains into confluence of sinuses, then usually left transverse.

Front 15

Inferior Sagital Sinus

Back 15

Along inferior border of falx cerebri. Drains into straight sinus.

Front 16

Straight sinus

Back 16

At junction of falx cerebri and tentorium cerebelli. Recieves great cerebral vein of Galen and inferior sagital sinus and drains into confluence of sinuses; usually left transverse.

Front 17

Great cerebral vein of Galen

Back 17

Drains choroid plexus of veins and drains into straight vein.

Front 18

Intercavernous sinus

Back 18

In diaphragma sellae. Connects left and right cavernous sinus.

Front 19

Basilar Sinus

Back 19

On clivus of occipital bone

Front 20

Occipital Sinus

Back 20

Borders foramen magnum and falx cerebelli

Front 21

Confluence of sinuses

Back 21

Between and posterior to transverse sinus. Drains superior sagital and straight sinuses. Drains into right or left transverse.

Front 22

Transverse Sinus

Back 22

At attachment of tentorium cerebelli to occipital bone. Drains into sigmoid sinus.

Front 23

Sigmoid sinus

Back 23

Along with inferior petrosal sinus, forms internal jugular vein. Drains anterior portion of transverse sinus.

Front 24

Superior Petrosal sinus

Back 24

Found along petrous ridge of temporal bone where tentorium cerebelli attaches. Connects cavernous sinus with junction of sigmoid and transverse sinuses.

Front 25

Inferior Petrosal Sinus

Back 25

Connects cavernous sinus to internal jugular vein. Forms internal jugular vein along with sigmoid sinus.

Front 26

Sphenoparietal Sinus

Back 26

Along lesser wing of sphenoid bone. Drains into cavernous sinus.

Front 27

Cavernous Sinus

Back 27

Lies on either side of the body of the sphenoid bone. Formed by Dura on all sides (periosteal and meningeal). Extends posteriorly from the petrous apex of the temporal bone to the superior orbital fissure anteriorly.
Drains Superior and inferior petrosal sinuses, superior ophthalmic veins, cerebral veins, and sphenoparietal veins. Communicates with pterygoid plexus.

Front 28

Contents of Cavernous Sinus

Back 28

CN3
CN4
V1 and 2 of CN5
CN6
Internal carotid artery
Venous blood

Front 29

Arachnoid Granulations

Back 29

Projections of arachnoid into dural sinuses especially the superior sagital. Drain cerebrospinal fluid to the blood circulation.

Front 30

Subarachnoid Space

Back 30

Filled with 150 mL of cerebrospinal fluid which gets turned over 3times/24 hours. Formed by choroid plexus in ventricles of brain. Major arteries and veins are in this space.

Front 31

Meningeal Nerves

Back 31

Superior to level of tentorium cerebelli is supplied by all 3 trigeminal branches. Inferior to the tentorium cerebelli is supplied by upper cranial nerves.

Front 32

Telencephalon

Back 32

Cerebral hemispheres with frontal, parietal, occipital, and temporal lobes.

Front 33

Diencephalon

Back 33

Superior to the sella turcica. Includes optic chiasm, optic nerves, pituitary gland, and pineal gland.

Front 34

Mesencephalon

Back 34

Consists of Pons and cerebellum.

Front 35

Pons

Back 35

Lies on clivus of occipital bone. Gives rise to trigeminal nerve.

Front 36

Pontomedullary Junction

Back 36

Exit point for abducens nerve (CN6) from brainstem.

Front 37

Pontocerebellar Angle

Back 37

Exit point of facial and vestibulocochlear nerves from brainstem (CN 7 and 8).

Front 38

Mylencephalon

Back 38

Medulla. Origins of CN 9, 10, and cranial portion of 11 are immedialtley posterior to inferior olive. CN12 exits brainstem just anterior to inferior olive.

Front 39

Branches of Vertebral Artery

Back 39

Posterior spinal arteries - descend and supply dorsal side of spinal chord
Anterior spinal arteries - join, descend, and supply ventral surface of spinal chord.
Posterior Inferior Cerebellar Arteries - Supply Cerebellum

Front 40

Branches of Basilar Artery

Back 40

Pontine branches - Numerous along length of basilar artery.
Labyrinth Artery - Enters internal acoustic meatus and supplies inner ear
Anterior inferior cerebellar artery - supplies cerebellum (terminal branch)
Posterior cerebral artery - supplies cerebral cortex. Communicates with ipsilateral internal carotid artery (Terminal branch).

Front 41

Path of Internal Carotid Artery

Back 41

Enters cranial cavity via carotid canal. Lies on top of foramen lacerum (filled with cartilage). Passes through cavernous sinus, gives off ophthalmic artery as it pierces dura. Continues into lateral fissure of brain.

Front 42

Branches of Internal Carotid Artery

Back 42

Ophthalmic Artery - Enters orbit through optic foramen with optic nerve.
Posterior communicating artery - communicates with posterior cerebral branch of basilar.
Anterior cerebral artery - Smaller of 2 terminal branches. Crosses optic nerve and travels into longitudinal fissure.
Middle cerebral artery - largest of two terminal branches.

Front 43

Cranial Nerves from the Telencephalon

Back 43

Olfactory Nerve (CN 1)

Front 44

Cranail Nerves from Diencephalon

Back 44

Optic Nerve (CN 2)

Front 45

Cranial Nerves from Midbrain

Back 45

-Occulomotor Nerve (CN 3)
-Trochlear Nerve (CN 4)

Front 46

Cranial Nerves from the Pons

Back 46

-Trigeminal Nerve (CN 5)
-Abducens Nerve (CN 6) (from pont-medullary junction)
-Facial Nerve (CN 7) (from ponto-cerebellar angle)

Front 47

Cranial Nerves from the Brainstem.

Back 47

Vestibulocochler Nerve (CN 8)

Front 48

Cranial Nerves from the Medulla

Back 48

-Glossopharyngeal Nerve (CN 9)
-Vagus Nerve (CN 10)
-Accessory Nerve (CN 11)
-Hypoglossal Nerve (CN 12)