Cranial Nerves

Question 1

What is the only cranial nerve that does not originate within the cranial cavity?

Answer 1

CN XI (Accessory)

It originates from the upper spinal cord, inferior to the occipital bone, enters the foramen magnum, then exits through the jugular foramen to reach its targets

Question 2

Which cranial nerves are sensory only?

Answer 2

(3 total) The SA nerves for special sensees:
I (olfactory)
II (optic)
VIII (vestibulocochlear)

Question 3

Which cranial nerves are motor only?

Answer 3

(5 total)
III (occulomotor)
IV (trochlear)
VI (abducent)
XI (accessory)
XII (hypoglossal)

Question 4

Which cranial nerves have mixed sensory and motor fibers?

Answer 4

V (trigeminal)
VII (facial)
IX (glossopharyngeal)
X (vagus)

Question 5

Which cranial nerves carry parasympathetic fibers?

Answer 5

III (occulomotor)
VII (facial)
IX (glossopharyngeal)
X (vagus)

Question 6

Where does sympathetic innervation in the head and upper neck originate?

Answer 6

preganglionic cell bodies reside in T1-T2 lateral horn gray matter and travel superiorly to the superior cervical ganglia, where they synapse with postganglionics, which follow the carotid arteries and branches in a plexus.

Question 7

What are the divisions of the CN V?

Answer 7

the trigeminal nerve has 3 divisions:
V1 (opthalmic)
V2 (maxillary)
V3 (mandibular)

Question 8

What is the name of CN IV?

Answer 8

trochlear

Question 9

What is the name of CN IX?

Answer 9

glossopharyngeal

Question 10

What is the name of CN XII?

Answer 10

hypoglossal

Question 11

What is the name of CN VI?

Answer 11

abducent

Question 12

Where is CN XI derived?

a. caudal brainstem
b. cranial brainstem
c. cranial spinal cord
d. caudal spinal cord

Answer 12

c. cranial spinal cord

caudal = tail end of body, so caudal brainstem would be the most inferior region of the brainstem (right around the foramen magnum)

cranial = close to the cranium so superior. The spinal cord ends superiorly near the foramen magnum as it meets the caudal brainstem.

Question 13

T or F: Cranial nerves form by fusion of dorsal and ventral roots.

Answer 13

F. Spinal nerves do this. Cranial nerves are already mixed by the time they originate from the brainstem.

Question 14

What type of fiber (GSA, GVA or SA) provides sensory innervation to the mucosal lining of the oral and nasal cavities?

Answer 14

GSA (the mucosal lining is derived from somatic mesoderm)

Question 15

What type of fiber provides sensory innervation to the mucosal lining of the esophagus, larynx and trachea?

Answer 15

GSA (these mucosal linings are derived from somatic mesoderm)

Question 16

Where would the cell body of a GSA fiber in a spinal nerve be found?

Answer 16

Dorsal Root Ganglia

Question 17

Where would the cell body of a GSA fiber in a cranial nerve be found?

Answer 17

various sensory ganglia

Question 18

Where would the cell body of a GVA fiber in a spinal nerve be found?

Answer 18

Dorsal Root ganglia

Question 19

Where would the cell body of a GSE fiber in a spinal nerve be found?

Answer 19

Ventral horn of spinal cord gray matter

Question 20

Where would the cell body of a GSE fiber in a cranial nerve be found?

Answer 20

brainstem motor nuclei

Question 21

Where would preganglionic sympathetic fibers in a cranial nerve be found

Answer 21

nowhere. They follow the carotid plexus

Question 22

Where would the cell bodies of parasympathetic fibers be found in a spinal nerve?

Answer 22

Gray matter of S2-S4

Question 23

Name the type of fibers found in CN I

Answer 23

SA

Question 24

Name the type of fibers found in CN II

Answer 24

SA

Question 25

Name the type of fibers found in CN III

Answer 25

GSE and GVE

Question 26

Name the type of fibers found in CN IV

Answer 26

GSE

Question 27

Name the type of fibers found in CN V

Answer 27

GSA and BE

Question 28

Name the type of fibers found in CN VI

Answer 28

GSE

Question 29

Name the type of fibers found in CN VII

Answer 29

GSA, SA, BE, GVE

Question 30

Name the type of fibers found in CN VIII

Answer 30

SA

Question 31

Name the type of fibers found in CN IX

Answer 31

GSA, GVA, SA, BE, GVE

Question 32

Name the type of fibers found in CN X

Answer 32

GSA, GVA, SA, BE, GVE

Question 33

Name the type of fibers found in CN XI

Answer 33

GSE

Question 34

Name the type of fibers found in CN XII

Answer 34

GSE

Question 35

Which nerve is associated with the first branchiomeric arch?

Answer 35

CN V3 (mandibular branch of trigeminal)

Question 36

Which nerve is associated with the second arch?

Answer 36

CN VII (facial)

Question 37

Which nerve is associated with the third arch?

Answer 37

CN IX (glossopharyngeal)

Question 38

Which nerve is associated with the fourth and sixth arches?

Answer 38

CN X (vagus)

Question 39

What do muscles of the tongue and eye develop from?

Answer 39

somite mesoderm

Question 40

What function do parasympathetics in the head serve?

Answer 40

constrict pupils contract ciliary muscles stimulate gland secretion (excluding sweat glands)

Question 41

What function do sympathetics serve in the head?

Answer 41

sweat gland function dilator pili muscle (if sympathetics fail, eyes will constrict. Think about fight or flight mode; when threatened, you will want to have the widest range of peripheral and distance vision possible so eyes will dilate) Also arrector pili muscle and superior tarsal muscle but we haven't learned these

Question 42

Where are postganglionic sympathetic cell bodies of the head and neck located?

Answer 42

superior cervical ganglia