Cranial Nerves

Question 1

What are the cranial nerves?

Answer 1

12 pairs of nerves which arise directly from the brain

Question 2

In the somatic NS, the segmental trunk nerves include which nerve fibres?

Answer 2

Afferent, inter, and efferent dorsal root ganglion

Ventral and dorsal fuse to 1 spinal nerve

Question 3

In the autonomic NS, what are the nerve fibres found in the segmental trunk?

Answer 3

Afferent
Inter
Preganglionic
Postganglionic 
(Additional ganglia where pre and post synapse)

Question 4

What are the differences between segmental trunk nerves and segmental head nerves? (3)

Answer 4

Somatic NS - No fusion of the 2 roots- dorsal and ventral roots are seperate
Leave via top instead of bottom
5th nerve - visceral efferent. Contains special visceral nerve fibres instead of normal efferent

Question 5

What are pharyngeal arches?

Answer 5

Tissues lying under the early brain which give rise to the structures of the head and neck

Question 6

Which pharyngeal arch fails to develop?

Answer 6

5

Question 7

CN I - name, function, composition

Answer 7

Olfactory
Smell
Sensory nerve fibres

Question 8

CN II - name, function, composition

Answer 8

Optical
Sight/vision
Sensory

Question 9

CN III - name, function, composition

Answer 9

Oculomotor
Movement of eyeball
Motor nerve fibres

Question 10

CN IV - name, function, composition

Answer 10

Trochlear
Movement of 1 eye muscle
Motor nerve fibres

Question 11

CN V - name, function, composition

Answer 11

Trigeminal
Touch and chewing
Both sensory and motor nerve fibres

Question 12

CN VI - name, function, composition

Answer 12

Abducent
Movement of eyeball laterally
Motor nerve fibres

Question 13

CN VII - name, function, composition

Answer 13

Facial
Facial expressions and taste
Both sensory and motor nerve fibres

Question 14

CN VIII - name, function, composition

Answer 14

Vestibulo-cochlear
Balance and hearing
Sensory nerve fibres

Question 15

CN IX - name, function, composition

Answer 15

Glosso-pharyngeal
Swallowing and taste
Both sensory and motor nerve fibres

Question 16

CN X - name, function, composition

Answer 16

Vagus
Respiration control, heartbeat control, peristalsis, taste
Both sensory and motor nerve fibres

Question 17

CN XI - name, function, composition

Answer 17

Accessory
Move neck and shoulders
Motor nerve fibres

Question 18

CN XII - name, function, compostion

Answer 18

Hypoglossal
Tongue movement
Motor nerve fibres

Question 19

Segement 1 - pharyngeal arch, ventral root nerve, dorsal root nerve

Answer 19

None
III - occulomotor
V - trigeminal (ophthalmic)

Question 20

Segement 2 - pharyngeal arch, ventral root nerve, dorsal root nerve

Answer 20

1
IV
V (maxillary and mandibular)

Question 21

Segement 3 - pharyngeal arch, ventral root nerve, dorsal root nerve

Answer 21

2
VI
VII

Question 22

Segement 4 - pharyngeal arch, ventral root nerve, dorsal root nerve

Answer 22

3
None
IX

Question 23

Segement 5 - pharyngeal arch, ventral root nerve, dorsal root nerve

Answer 23

4
None
X/XI (vagus-accessory complex)

Question 24

Segement 6 - pharyngeal arch, ventral root nerve, dorsal root nerve

Answer 24

5
XII
None

Question 25

Segement 7 - pharyngeal arch, ventral root nerve, dorsal root nerve

Answer 25

6
XII
X/XI (vagal-accessory complex)