Cranium, Meninges, etc...

Question 1

What passes through the optic canal and what does it do?

Answer 1

CNII (Optic Nerve)…carries visual information from the retina of the eye back to the brain

Question 2

What passes through the superior orbital fissure?

Answer 2

CN III (occulomotor), IV (Trochlear), VI (Abducens), and the V1 branch of CN V (Trigeminal)

Occulomotor, trochlear, and abducens allow for control of the orbital muscles which move the eye and constrict the pupil

Question 3

What passes through the foramen ovale

Answer 3

V3

Question 4

What passes through the foramen spinosum?

Answer 4

Middle meningeal arteryenters the skull

Question 5

Internal carotid artery gains entry into the skull by entering through which pathway?

Answer 5

Carotid foramen, passes through a bony canal, and then enters the skull via the carotid canal

Question 6

CN VII exits the skull via

Answer 6

Stylomastoid foramen

Question 7

CN VIII exits skull via

Answer 7

external auditory meatus

Question 8

The jugular foramen permits exit of what

Answer 8

CN IX, X, II

Question 9

CN XII exits the calderium via the hypoglossal canal

Answer 9

ok

Question 10

How many layers of meninges are there?

Answer 10

3
From the brain out: - Pia Mater: very thin, tight against brain surface
- Arachnoid mater: Thicker
- Dura Mater: double membrane, Meningeal layer closest to the brain and periosteal layer furthest out

Question 11

The two layers of the Dura mater separate where to form what

Answer 11

Separate in the midline and at the lateral aspects to form large venous sinuses known as the superior sagittal sinus and the lateral sinuses.

Question 12

The meningeal layer of the Dura mater creates a thick membrane called the —–, that separates left and right cerebral hemisphere. Also creates another membrane that separates the cerebral hemispheres from the cerebellum

Answer 12

falx cerebri

Tentorum Cerebelli

Question 13

Three important spaces associated with the meninges?

Answer 13

• Epidural and Subdural spaces, these are called potential spaces.
• Epidural bleeding is usually arterial, subdural usually venous
• Subarachnoid: True space that is lined by the arachnoid above and the pia mater below. The bulk of the CSF, large blood vessels all lie in subarachnoid

Question 14

What 2 pairs of arteries supply the brain

Answer 14

Right and Left Internal Carotid- Formed from division of common carotids just below the angle of jaw. Externals supply the face, scalp and meninges

Right and Left Vertebral-

Question 15

Internal carotid arteries become what once they get inside the skull?

Answer 15

Middle Cerebral and Anterior cerebral

Question 16

Opthalmic arteries branch off of what

Answer 16

Internal carotid, they are the first branch

Question 17

Right and left vertebral arteries originate from where?

Answer 17

Subclavian

Question 18

Why is the Circle of Willis important

Answer 18

It provides the potential for collateral blood flow if one or more of the four major arteries is obstructed or occluded

Question 19

Note that the lesser wing of the sphenoid bone (separating the anterior fossa of the skull from the middle) and the petrous ridge of the temporal bone (sep middle from posterior) create bony ridges which the skull can rub against and be injured if it accelerates or decelerates quickly

Answer 19

ok

Question 20

Dura mater continues out into the peripheral nerve to form what layer

Answer 20

epineurium

Question 21

Arachnoid continues out into the peripheral nerve to form what layer?

Answer 21

Perineurium