Nerve Supply to Head

Question 1

3 divisions of Trigeminal

Answer 1

1. Mandibular
2. Maxillary
3. Ophthalmic

Question 2

Oculomotor n. (III)

Answer 2

Somatic/visceral efferents ONLY
Enters orbit via orbital fissure
Preganglionic sympathetic fibers to ciliary ganglion
Innervates almost all eye muscles

Question 3

Clinical signs of oculomotor n damage

Answer 3

Pupillary dilation
Lateroventral strabismis
Ptosis

Question 4

Trigeminal n (V)

Answer 4

Mixed nerve, largest cranial n
Sensory to skin of head, oral/nasal cavities
Motor to masticatory muscles

Question 5

Auriculotemporal n damage

Answer 5

Masseter atrophy

Question 6

Facial n

Answer 6

Mixed
Enters cranium via stylomastoid foramen
Sensory only to concave surface of pinna and tongue (taste)
Motor to muscles of jaw opening, facial expression
Parasympathetic to salivary, tear glands

Question 7

Yellow starthistle poisoning

Answer 7

Causes neurological signs, occipitomandibularis is tetanically contracted

Question 8

Glossopharyngeal n (IV)

Answer 8

Mixed nerve
Enters cranium via foramen lacerum
Innervated 1/3 of tongue, pharyngeal muscles, carotid sinus, parotid salivary glands

Question 9

Clinical signs of glossopharyngeal n damage

Answer 9

dysphagia

Question 10

Vagus (X)

Answer 10

Mixed nerve
Enters cranium via foramen lacerum
Innervated pharynx/larynx and associated muscles, cervical-thoracic-abdominal viscera

Question 11

Clinical signs of vagus n damage

Answer 11

Dysphagia
Laryngeal Hemiplagia (roaring)

Question 12

Roaring

Answer 12

Laryngeal hemiplegia
Due to damage to recurrent laryngeal n., resulting in atrophy of the cricoarytenoideus dorsalis (most commonly the L because of positioning near lymph nodes).
Clinical signs include inspiratory noise and exercise intolerance.
Causes occlusion of laryngeal cavity
Can be surgically corrected via laryngeal prosthesis (tie back) or ventriculectomy