Intro to the skull and the cranial cavity

Question 1

What comes out of the Cribiform Plate?

Answer 1

CN1

Question 2

What comes out of the Optic Canal?

Answer 2

CNII

Question 3

What comes out of the superior orbital fissure?

Answer 3

CN III, IV, VI, V1

Question 4

What comes out of the foramen lacerum?

Answer 4

Nothing directly

Question 5

What comes out of the Internal Acoustic Meatus?

Answer 5

CN VII, VIII

Question 6

What comes out of the hypoglossal canal?

Answer 6

CN XII

Question 7

What comes out of the Jugular Foramen?

Answer 7

IJV, CN IX, CN X and CN XI

Question 8

What comes out of the stylomastoid foramen?

Answer 8

Trunk of the facial nerve

Question 9

What comes out of the foramen spinosum?

Answer 9

the middle meningeal artery

Question 10

What comes out of the foramen ovale?

Answer 10

V3

Question 11

What comes out of the foramen rotundum

Answer 11

V2

Question 12

What’s in the sella turcica?

Answer 12

The pituitary gland

Question 13

What’s the big deal about the cavernous sinus?

Answer 13

CN III, IV, VI, V1, V2 pass through cavernous sinus and can be affected by an infection there.

Question 14

What can one sign of an internal carotid artery aneurysm be?

Answer 14

An aneurysm of the ICA can also affect CN VI, affecting lateral eye movement

Question 15

What innervates the anterior cranial fossa?

Answer 15

V1, V2, V3

Question 16

What innervates the middle cranial fossa?

Answer 16

V2 and V3

Question 17

What innervates the floor of the posterior cranial fossa?

Answer 17

C1 and C2

Question 18

What innervates the tentorium cerebelli

Answer 18

Tentorial branch of V1

Question 19

What innervates the Falx Cerebri

Answer 19

Branches of CN V1

Question 20

What provides the blood supply to the dura?

Answer 20

• Middle Meningeal artery
• Meningeal branches of occipital a.
• Meningeal brs. of ascending pharyngeal a.

Question 21

epidural hematoma

Answer 21

• Arterial in origin (torn branch of middle meningeal artery is the most common source secondary to skull fracture)
• Blood collects in epidural space
• The epidural space is a potential space, manifesting almost exclusively in the event of hemorrhage

Question 22

epidural hematoma (imaging)

Answer 22

• lens shaped accumulation of blood

* arterial blood is whiter than the brain on non-contrast CT

Question 23

Subdural hemorrhage (SDH)

Answer 23

• usually Venous in origin
• Follows head trauma where the brain moves within the skull
• Blood collects in subdural space (a potential space)
• Crescent shaped accumulation of blood

Question 24

Subarachnoid hemorrhage (SAH)

Answer 24

• usually arterial in origin
• often due to ruptured intracranial aneurysm
• Can also be associated with trauma
• Blood accumulates in the subarachnoid space, a true space filled with CSF
• Blood mixes with CSF and can diffuse widely
• Basilar Tip Aneurysm is associated with subarachnoid hemorrhage
• irregularly shaped on CT