WK7 - Head and Neck Anatomy (Cranial nerves)

Question 1

Cranial nerve I

Answer 1

Olfactory
- enters cranial cavity through cribiform plate

Function:
- smell

Question 2

Cranial nerve II

Answer 2

Optic

• not a true CN but extensin of brain
• enters cranial cavity through optic canal

Function:
- vision

Question 3

Cranial nerve III

Answer 3

Oculomotor
- exits cranial cavity through superior orbital fissure

Function:

• motor to most (5 out of 7) extra-ocular muscles (move eyeball)
• parasympathetic (Pupillary constriction, accommodation of lens)

Question 4

Cranial nerve IV

Answer 4

Trochlear
0 exits cranial cavity through superior orbital fissure

Function:
- motor to one extra-ocular muscle

Question 5

Cranial nerve V

Answer 5

Trigeminal
- has 3 divisions:
V1 - opthalmic (enters cranial cavity through superior orbital fissure)
V2 - maxillary (enters cranial cavity through foramen rotundum)
V3 - mandibular (enters cranial cavity through foramen ovale)

Function:

• sensory from most of head, including ALL TEETH
• motor to muscles of mastication

Question 6

Cranial nerve VI

Answer 6

Abducent
- enters cranial cavity through superior orbital fissure

FUnction:
- motor to one extra-ocular muscle

Question 7

Cranial nerve VII

Answer 7

Facial
- exits cranial cavity through internal auditory meatus and stylomastoid foramen

Function:
- motor to muscles of facial expression
- taste from anterior 2/3 tongue
parasympathetic (lacrimal gland, submandibular and sublingual salivary glands)

Question 8

Cranial nerve VIII

Answer 8

Vestibulocochlear
- enters cranial cavity through internal auditory meatus

Function:
- hearing and balance

Question 9

Cranial nerve IX

Answer 9

Glossopharyngeal
- enters cranial cavity through jugular foramen

Function:

• motor to one muscle of pharynx
• taste from posterior 1/3 of tongue
• visceral sensory from carotid body and sinus
• parasympathetic (parotid salivary gland)

Question 10

Cranial nerve X

Answer 10

Vagus
- enters cranial cavity through jugular foramen

Function:

• motor to soft palate, pharynx and larynx
• visceral sensory from most cervical, thoracic and abdominal viscera
• parasympathetic (most cervical, thoracic and abdominal viscera)

Question 11

Cranial nerve XI

Answer 11

Accessory

• unusual - arrives from C1 to C5 rather than brain
• exits cranial cavity through jugular foramen

Function:
- motor to sternocleidomastoid and trapezius muscles

Question 12

Cranial nerve XII

Answer 12

Hypoglossal
- exits cranial cavity through hypoglossal canal

Function:
- motor to all intrinsic and most extrinsic muscles of tongue