Cranial Nerve Skull Foramina

Question 1

cribriform plate

Answer 1

olfactory nerve bundles (CN I)

Question 2

optic canal

Answer 2

Optic Nerve (CN II)
Ophthalmic artery

Question 3

superior orbital fissure

Answer 3

• Oculomotor Nerve (CN III)
• Trochlear N (CN IV)
• Trigeminal N, ophthalmic branch (CN V,1) : lacrimal, frontal, nasociliary branches
• Abducens N (CN VI)
• Superior ophthalmic vein

Question 4

foramen rotundum

Answer 4

Trigeminal N., Maxillary branch (CN V,2)

Question 5

foramen ovale

Answer 5

• Trigeminal N., Mandibular branch (CN V,3)
• Accessory meningeal artery
• lesser petrosal n (occasionally)

Question 6

foramen spinosum

Answer 6

• middle meningeal a/v

- meningeal branch of mandibular n (CN V,3)

Question 7

foramen lacerum

Answer 7

greater petrosal nerve crosses this space

Question 8

carotid canal

Answer 8

• internal carotid artery

- internal carotid nerve plexus

Question 9

internal acoustic meatus

Answer 9

• Facial N (CN VII)
• Vestibulocochlear N (CN V VIII)
• labyrinthine a

Question 10

jugular foramen

Answer 10

• inferior petrosal venous sinus
• Glossopharyngeal N (CN IX)
• Vagus N (CN X)
• Accessory N (CN XI)
• sigmoid venous sinus
• posterior meningeal artery

Question 11

hypoglossal canal

Answer 11

• Hypoglossal N (CN XII)

Question 12

foramen magnum

Answer 12

• medulla oblongata
• meninges
• vertebral arteries
• meningeal branches of vertebral arteries
• spinal roots of accessory nerves

Question 13

Which m. originates from the scaphoid fossa?

Answer 13

tensor veli palatini m.

Question 14

Which n. runs through the petrotympanic fissure?

Answer 14

chorda tympani (br. of facial n.)

Question 15

Which n. runs through the tympanic canaliculus?

Answer 15

tympanic n. (n. of Jacobson)

Question 16

two parts of the dura mater

Answer 16

cranial dura

spinal dura

Question 17

two layers of the cranial dura

Answer 17

periosteal outer layer

meningeal inner layer

(normally fused)

Question 18

dural partitions

Answer 18

(reflections/infoldings of inner meningeal layer of dura mater)

• Falx Cerebri
• Falx Cerebelli
• Tentorium Cerebelli
• Diaphragma Sellae

Question 19

Falx cerebri

Answer 19

separates cerebral hemispheres

Question 20

Falx cerebelli

Answer 20

lies between the cerebellar hemispheres

Question 21

Tentorium cerebelli

Answer 21

separates occipital lobes of cerebrum from the cerebellum

Question 22

Diaphragma sellae

Answer 22

lies over the pituitary gland

Question 23

dural venous sinuses

Answer 23

endothelial lined spaces formed between the meningeal and periosteal layers of the dura

important for draining blood into IJV

Question 24

Emissary v. drain ______

while diploid v. drain ______

Answer 24

Emissary v. drain the SCALP

while diploid v. drain BONE

Question 25

Path of superior sagittal sinus drainage

Answer 25

superior sagittal sinus --> confluence of sinuses --> R transverse sinus --> sigmoid sinus --> IJV

Question 26

Path of inferior sagittal sinus drainage

Answer 26

inferior sagittal sinus --> confluence of sinuses --> L transverse sinus --> sigmoid sinus --> IJV

Question 27

Path of occipital sinus drainage

Answer 27

occipital sinus --> confluence of sinuses --> L transverse sinus --> sigmoid sinus --> IJV

Question 28

cavernous sinus drainage

Answer 28

either superior and inferior petrosal sinuses

Question 29

superior petrosal sinus drainage

Answer 29

superior petrosal sinus --> transverse sinus --> sigmoid sinus --> IJV

Question 30

inferior petrosal sinus drainage

Answer 30

inferior petrosal sinus --> sigmoid sinus --> IJV

Question 31

cavernous sinuses | location, drain what?

Answer 31

paired dural venous sinuses. found on either side of sella turcica. drains the orbit, anterior aspect of brain, and sphenoparietal sinus.

Question 32

content of cavernous sinuses

Answer 32

internal carotid a. w/ surrounding sympathetic plexus. CN III, CN IV, CN V1, CN V2, and CN VI (embedded in lateral wall of the sinus)

Question 33

cavernous sinus thrombosis signs/sx

Answer 33

``` pain conjunctival chemosis proptosis ptosis (CNIII) dilated pupil (CNIII) corneal reflex lost (CNV1) double vision facial sensory loss ophthalmoplegia (CNIII, CNIV, CNVI) ```

Question 34

cavernous sinus thrombosis tx

Answer 34

- vigorous and early use of anticoagulants - abx - drainage and elimination of infection are essential.

Question 35

innervation of dura on floor of anterior cranial fossa

Answer 35

meningeal branches of CN V (V1, V2, V3)

Question 36

innervation of middle cranial fossa dura

Answer 36

meningeal branches of CN V (V2, V3)

Question 37

innervation of tentorium cerebelli and posterior falx cerebri

Answer 37

tentorial branch of CN V1

Question 38

innervation of anterior falx cerebri

Answer 38

anterior meningeal branches of ethmoidal n. (from nasociliary n.

Question 39

Does the arachnoid mater contain vascular structures?

Answer 39

No, it's avascular. All cerebral a. and v. --> in subarachnoid space.

Question 40

Arachnoid granulations

Answer 40

small projections to venous sinuses to drain CSF

Question 41

Granular foveola

Answer 41

impressions on calvaria made by arachnoid granulations

Question 42

Pia mater

Answer 42

vascular layer that is adherent to the brain surface, extends w/ cerebral sulk and cover gyri

Question 43

arachnoid trabeculae

Answer 43

loosely connect arachnoid mater to pia mater

Question 44

extracerebral bleeding

Answer 44

bleeding between bony calvarium and soft tissue of the brain increases intracranial pressure

Question 45

epidural hematoma

Answer 45

Usually due to ruptured middle meningeal a. Blood contained between durra and inner table of the skull Sx: initial lucid interval, HA, vomiting, clear fluid from nose/mouth, loss of consciousness 3-8 hr later

Question 46

subdural hematoma

Answer 46

Blood between brain parenchyma and dural membranes Elderly at risk (innate atrophy of cerebral cortex --> smaller brain vol --> inc space in subdural compartment --> inc stretch on bridging v. between skull and cerebral surface) Concave lens shape

Question 47

subarachnoid hematoma

Answer 47

bleeding between arachnoid and pia mater causes: birth trauma, hypoxic ischemic injury, rupture of aneurysm blood obstructs CSF reabsorption --> increased ICP w/ hydrocaphalus tx: placement of ventricular drains and shunting system (ventriculoperitoneal shunt)

Question 48

which a. commonly exhibit Berry aneurysms

Answer 48

anterior cerebral a. | anterior communicating a.

Question 49

circle of Willis

Answer 49

pt of cerebral circulation - anterior cerebral a. - anterior communicating a. - internal carotid a. (L/R) - posterior cerebral a. (L/R) - posterior communicating a. (L/R)

Question 50

paranasal sinuses

Answer 50

- mucosa-lined, air-filled spaces - found in frontal/sphenoid/ethmoid/maxillary bones ``` - reduce weight of skull enhance resonance of voice warm and humidify inspired air absorb shock contrib to facial growth ```

Question 51

sinusitis

Answer 51

inflammation of tissues lining the sinuses causes: common cold, allergic rhinitis, nasal polyps, deviated septum

Question 52

What accounts for up to 40% of maxillary sinusitis cases?

Answer 52

``` odotogenic sinusitis (infection spreads from teeth in upper jaw to maxillary sinus) ```