Cranial Nerves Part 1

Question 1

What is the only sensory system that does not go through the thalamus to get to the cerebral cortex?

Answer 1

Olfactory system

Question 2

The right brain sees the ______ visual field

Answer 2

Left

Question 3

The left brain sees the ______ visual field

Answer 3

Right

Question 4

Unilateral anopsia is observed in your pt. Where on the optic n. tract is the lesion?

Answer 4

anterior to the optic chiasm

Question 5

Left visual field homonymous hemianopsia is noted. Where is the lesion?

Answer 5

Behind the optic chiasm on the right side of the optic n. tract

Question 6

Bitemporal hemianopsia is observed d/t an enlarged pituitary gland. Where is the lesion/pressure?

Answer 6

On the optic chiasm

*only the medial vision is working because the temporal fibers don’t cross the optic chiasm and they see the medial visual fields

Question 7

Which CNs are responsible for extra-ocular conjugate movement?

Answer 7

CN III (oculomotor n.)

CN IV (trochlear n.)

CN VI (abducens n.)

Question 8

Where does CN III arise from?

Answer 8

Interpeduncular fossa (also emerges around the posterior cerebral arteries)

Question 9

What muscle of the eye allows it to focus on an object?

Answer 9

Ciliary m.

Question 10

When focusing on a distance object, the ciliary m. _______ and the lens gets ______

Answer 10

relaxes

thinner

Question 11

When focusing on a close object, the ciliary m. _______ and the lens gets _______

Answer 11

contracts

thicker

Question 12

What CN does most of the work w/ the eye?

Answer 12

CN III (oculomotor n.)

Question 13

What CN rotates eye diagonally down and out?

Answer 13

CN IV (trochlear n.)

Question 14

What is the fx of CN IV?

Answer 14

rotates the eye diagonally down and out

Question 15

What CN innervates the Superior oblique m.?

Answer 15

CN IV (trochlear n.)

Question 16

What CN innervates the lateral rectus?

Answer 16

CN VI (abducens n.)

Question 17

What CN (including the specific branch) innervates the medial rectus m.?

Answer 17

Inferior branch of CN III (oculomotor n.)

Question 18

What CN rotates the eye out?

Answer 18

CN VI (abducens n.)

Question 19

Pt. has strabismus and their extraocular muscles are anatomically normal. What nerve is the lesion on?

Answer 19

CN VI (abducens n.)

Question 20

CN that emerges from the ventrolateral pons

Answer 20

CN V (Trigeminal n.)

Question 21

CN that arises in the pontomedullary grove

Answer 21

CN VI (abducens n.)

Question 22

The only CN that emerges dorsally

Answer 22

CN IV (trochlear n.)

Question 23

The only CN that is crossed

Answer 23

CN IV (trochlear n.)

Question 24

Name the 3 divisions of CN V

Answer 24

V1 - opthalamic n.

V2 - maxillary n.

V3 - mandibular n.

Question 25

Supplies gen. sensation from anterior nose to upper face and forehead

Answer 25

V1 (opthalamic n.) branch of CN V

Question 26

Supplies gen. sensation from upper lip to lower eyelid and back to nasopharyx

Answer 26

V2 (maxillary n.) branch of CN V

Question 27

Supplies gen. sensation from lower lip back to TMJ and posterior temple

Answer 27

V3 (mandibular n.) branch of CN V

Question 28

What CN causes pupil constriction?

Answer 28

CN III (oculomotor n.)

Question 29

Parasympathetic stimulation = pupils are ________

Answer 29

constricted

Question 30

What type of herniation affects CN III?

Answer 30

Uncal herniation

Question 31

What br. of CN V leaves the skull via the foramen ovale?

Answer 31

V3 (mandibular n.)

Question 32

What br. of CN V leaves the skull via the foramen rotundum?

Answer 32

V2 (maxillary n.)

Question 33

What br. of CN V leaves the skull via the superior orbital fissure?

Answer 33

V1 (Opthalamic n.)

Question 34

What CN branch innervates the pterygoid muscles, massetter muscles, temporalis muscles?

Answer 34

V3 Mandibular branch of CN V

Question 35

What space does the medial & lateral pterygoid muscles reside?

Answer 35

Infratemporal fossa