Specifics for Cranial Nerves

Question 1

Which cranial nerves carry parasympathetic fibers?

Answer 1

CN III (Oculomotor), VII (Facial), IX (Glossopharyngeal), X (Vagus)

Question 2

Which cranial nerves are special sense?

Answer 2

CN I, II, VII, VIII, IX, X

Question 3

Which is the only cranial nerve to enter cranial cavity in anterior fossa?

Answer 3

Olfactory Nerve (I)

Question 4

Explain location of fibers for CN I

Answer 4

Bundles of fibers pierce cribiform plate and synapse in olfactory bulb

Question 5

What is CN II?

Answer 5

(Optic) BUT is not a nerve - is extension of brain (a tract) that includes the retina

Question 6

Explain chiasma of CN II fibers

Answer 6

Portion of fibers from nasal 1/2 of each optic “nerve” cross to other “nerve” at chiasma

Question 7

When fibers of CN II leave orbit, where do they enter skull?

Answer 7

Optic canal

Question 8

CN III provides motor to which muscles?

Answer 8

5 of 7 orbital muscles

Question 9

Which orbital muscles are NOT innervated by CN III?

Answer 9

Superior oblique (CN IV) and Lateral Rectus (CN VI)

Question 10

Parasympathetic preganglionic fibers from CN III go to which ganglion?

Answer 10

Ciliary ganglion

Question 11

After going to ciliary ganglion, where to fibers from CN III go?

Answer 11

On to sphincter pupillae (constriction) and ciliary muscle (more convex lens) via short ciliaries

Question 12

What muscle does CN IV innervate?

Answer 12

Superior oblique

Question 13

Which is the only nerve to exit dorm of brain stem?

Answer 13

CN IV (trochlear)

Question 14

Which nerve provides motor to lateral rectus?

Answer 14

Abducens CN VI

Question 15

What does lateral rectus do?

Answer 15

Abducts