L18 - Cranial Nerves

Question 1

Vagus

Answer 1

• “Wanderer”, travels to thorax and abdomen
• All others are concerned with regions of head and neck

Question 2

Cranial Nerves (12)

Answer 2

Only One Of The Two Athletes Felt Very Good Victorious And Healthy

1. Olfactory
2. Optic
3. Oculomotor
4. Trochlear
5. Trigeminal
6. Abucens
7. Facial
8. Vestibulocochlear
9. Glossopharyngeal
10. Vagus
11. Accessory
12. Hypoglossal

Question 3

Sensory or Motor or Both?

Answer 3

Some Say Marry Money But My Brother Says Big Brains Matter More

Question 4

Hierachy of motor neurons:

Answer 4

Upper motor neurons:
- Within motor cortex and brainstem (Extrapyramidal neurons)

Lower motor neurons:
- In anterior horn of spinal cord and cell body in CNS, axon in PNS

Question 5

Olfactory nerve (CN 1)

Answer 5

Hole: Cribriform foramina
Function: S, olfaction.

Question 6

Optic nerve (CN 2)

Answer 6

Hole: Optic canal (sphenoid bone)
Function: S, vision

Question 7

Oculomotor (CN 3)

Answer 7

Hole: Superior orbital fissure (Oculomotor, trochlear, abducens all through this)

Function: M, 4 extrinsic eye muscles, levator pulpebrae superioris

Question 8

Trochlear (CN 4)

Answer 8

Hole: Superior orbital fissure (Oculomotor, trochlear, abducens all through this)
Function: M, superior oblique muscle

Question 9

Trigeminal nerve (CN 5)

Answer 9

Hole:
Ophthalmic branch (V1): Superior orbital fissure
Maxillary branch (V2): Foramen rotundum
Mandibular branch (V3): Foramen ovale

Function: B, M = muscles of mastication, S = scalp, nasal, oral cavity, teeth, ear, etc.

Question 10

Abducens (CN 6)

Answer 10

Hole: Superior orbital fissure (Oculomotor, trochlear, trigeminal first branch, abducens all through this)
Function: M, lateral rectus

Question 11

Facial nerve (CN 7)

Answer 11

Hole: Internal acoustic meatus (same as vestibulo)
Function: motor = Sublingual, submandibular… sensory = taste on anterior 2/3 of tongue (S), facial expression muscles (M)??

Question 12

Vestibulocochlear nerve (CN 8)

Answer 12

Hole: Internal acoustic meatus
Function: S, hearing (cochlear) and balance (vestibular)

Question 13

Glossopharyngeal nerve (CN 9)

Answer 13

Hole: Jugular foramen (glossopharyngeal, vagus, accessory
Function: B, taste and sensation in posterior 1/3 of tongue/throat (S), 1 pharyngeal muscle (M)

Question 14

Vagus nerve (CN 10)

Answer 14

Hole: Jugular foramen (glossopharyngeal, vagus, accessory
Function: B, sensation of throat/viscera (S), most pharyngeal (M), laryngeal (M)

Question 15

Accessory nerve (CN 11)

Answer 15

Hole: Jugular foramen (glossopharyngeal, vagus, accessory
Function: M, neck and shoulder movement (sternocleidomastoid and trapezius muscles)

Question 16

Hypoglossal nerve (CN 12)

Answer 16

Hole: Hypoglossal canal
Function: M, tongue movement

Question 17

Corneal blink reflex

Answer 17

1. Trigeminal nerve, senses
2. Synapse
3. Facial nerve, blink

Question 18

Pupillary light reflex (squint)

Answer 18

• Light enters
• Optic nerve senses
• Trochlea