Cranial Nerves VI - XII

Question 1

What is the 6th cranial nerve and describe its route

Answer 1

Abducent nerve
Hind brain b/w Pons and Medulla Oblongata –> Cavernous Sinus –>
Sup. Orb. Fissure –> Lateral Rectus muscle

Question 2

Whats the clinical test for the abducent nerve

Answer 2

lateral eye movement

Question 3

What can be the effects of damage to the abducent nerve

Answer 3

inability to rotate eye laterally; at rest – eye rotates medially

Question 4

Which nerves innervate which parts of extra ocular movement

Answer 4

Abducens (6) - lateral rectus muscle, moves eye laterally
Trochlear (4) - superior oblique muscle, moves eye down and rotates internally
Oculomotor (3) - all other eye muscle movement, also raises lid and mediates pupillary constriction

Question 5

What is the 7th cranial nerve and describe its route

Answer 5

Facial

Hind brain –> Internal Acoustic Meatus –> Geniculate nucleus –> Stylomastoid foramen –> Parotid gland

Question 6

What are the branches of the facial nerve

Answer 6

• Temporal
• Zygomatic
• Buccal
• Mandibular
• Cervical

Question 7

What is the chordates tympani

Answer 7

nerve of the facial nerve that joins the lingual division of the mandibular nerve

Question 8

What is the greater petrosal nerve

Answer 8

Branch of facial

innervates lacrimal gland and taste buds on anterior part of palate

Question 9

What is the function of the facial nerve

Answer 9

facial expression; sense of taste

Question 10

What is the clinical test for the facial nerve

Answer 10

motor functions – close eyes, smile, whistle, frown, raise eyebrows; taste

Question 11

What can be the effects of damage to the facial nerve

Answer 11

inability to control facial muscles; distorted sense of taste, dry eyes

Question 12

What is the 8th cranial nerve and describe its route

Answer 12

Vestibulocochlear

Hind brain –> IAM –> Vestibular and cochlear fibres

Question 13

What is the function of the vestibulocochlear (8th) nerve

Answer 13

hearing and equilibrium

Question 14

What are the clinical tests for the vestibulocochlear (8th) nerver

Answer 14

test hearing, balance, and ability to walk a straight line

Question 15

What can be the effects of damage to the vestibulocochclear (8th) nerve

Answer 15

deafness, dizziness, nausea, loss of balance, and nystagmus

Question 16

What is the 9th cranial nerve and describe its route

Answer 16

glossopharyngeal nerve
originates from the medulla oblongata
exits the skull through the jugular foramen

Question 17

What do the motor and sensory fibres of the glossopharyngeal nerve innervate

Answer 17

Motor fibres - stylopharyngess muscle (of the pharynx)

Sensory fibres - oropharynx and posterior tongue

Question 18

What is the function of the glossopharyngeal nerve

Answer 18

swallowing, salivation, gagging; touch, pressure, taste, and pain sensations from tongue, pharynx, and outer ear

Question 19

What is the clinical test for the glossopharyngeal nerve

Answer 19

gag reflex, swallowing, and coughing

Question 20

What can be the effects of damage to the glossopharyngeal nerve

Answer 20

difficulty swallowing

Question 21

What is the 10th cranial nerve and describe its route

Answer 21

the vagus nerve

arises from the medulla oblongata and exits the skull at the jugular foramen

Question 22

What do the sensory fibres of the vagus nerve innervate

Answer 22

external auditory meatus & tympanic membrane

Question 23

What do the motor fibres of the vagus nerve innervate

Answer 23

the muscles of the larynx, respiratory passages, lungs, heart, oesophagus, stomach, small intestine, most of the large intestine & the gallbladder.

Question 24

What are the functions of the vagus nerve

Answer 24

swallowing; taste; speech; respiratory, CV, and GI regulation; sensations of hunger, fullness, and intestinal discomfort

Question 25

What can be the effects of damage to the vagus nerve

Answer 25

hoarseness or loss of voice; impaired swallowing and GI motility

Question 26

What is the 11th cranial nerve and describe its route

Answer 26

the accessory nerve originates from both the medulla oblongata and from the spinal cord. emerges out through the jugular foramen

Question 27

What does the accessory (11th) nerve innervate

Answer 27

Trapezius and sternocleidomastoid muscles

Question 28

What is the function of the accessory nerve

Answer 28

head, neck, and shoulder movements

Question 29

What are the clinical tests for the accessory nerve

Answer 29

rotate head and shrug shoulders against resistance

Question 30

What can be the effects of damage to the accessory nerve

Answer 30

impaired movement of head, neck, and shoulders; paralysis of sternocleidomastoid

Question 31

What is the 12th cranial nerve and describe its route

Answer 31

Hypoglossal Originates in the medulla oblongata exits skull through the hypoglossal canal

Question 32

What does the hypoglossal nerve innervate

Answer 32

the muscles of the tongue

Question 33

What are the functions of the hypoglossal nerve

Answer 33

tongue movements of speech, food manipulation, and swallowing

Question 34

What is the clinical test for the hypoglossal nerve

Answer 34

tongue function

Question 35

What can be the effects of damage to the hypoglossal nerve

Answer 35

difficulty in speech and swallowing; atrophy of tongue; inability to stick out (protrude) tongue