Cranial Nerves - Function

Question 1

CN II - Optic - Function

Answer 1

• Vision

Question 2

CN VI - Abducent - Function

Answer 2

• Eye movement (abduction)

Question 3

CN VII - Facial - Function

Answer 3

• Facial expression
• Taste
• Salivation (submandibular and sublingual glands)
• Lacrimation
• Mandibular depression
• Contributes to hyoid elevation

Question 4

CN IX - Glossopharyngeal - Function

Answer 4

• Laryngeal elevation
• Dilation of pharynx via stylopharyngeus (contributes to epiglottic excursion)
• Taste/sensation
• Sensory portion of pharyngeal gag
• Salivation (parotid gland)

Question 5

XII - Hypoglossal - Function

Answer 5

Intrinsic muscles:

• shortening, cupping, narrowing, elongating, flattening

Extrinsic muscles:

• drawing tongue upwards, forwards, backwards, retraction and depression
• Backward movement of tongue to soft palate
• Draws hyoid bone up and forward
• Depresses mandible

Question 6

CN V - Trigeminal - Function (Motor)

Answer 6

Branch 3 - Motor:

• Upward/anterior movement of larynx
• Backward movement of tongue to soft palate
• Palatal elevation (tenses soft palate)
• Posterior pharyngeal wall constriction

Question 7

CN X - Vagus - Function (Motor)

Answer 7

• Elevation/depression of soft palate
• Elevation of posterior tongue
• Elevation/closure of larynx
• Lowering of larynx after swallow

RLN - muscles of intrinsic larynx

SLN - cricothyroid, pharyngeal contraction, relaxation of cricopharyngeal muscle, esophageal peristalsis, cardiac, GI tract, respiration

Question 8

CN I - Olfactory - Function

Answer 8

• Smell

Question 9

CN XI - Accessory - Function

Answer 9

Cranial Accessory

• Raises soft palate
• Narrows and elevates of lateral pharyngeal wall
• Narrows and elevates posterior tongue

Spinal Accessory

• Neck & Shoulder Movement

Question 10

CN V - Trigeminal - Function (Sensory)

Answer 10

Branches 1 and 2 - Sensory:

• Face, cheeks, lips, jaw, eyes, etc (pain, temp, touch)

Branch 3 - Sensory:

• Sensation of superficial & deep facial structures, muccous membrane of upper mouth, palate, tongue
• Sensation of shape and texture in mouth
• Sensation to palate & pharynx

Question 11

CN III - Oculomotor - Function

Answer 11

• Eyelid opening
• Eyeball Movement
• Pupil constriction

Question 12

CN VIII - Vestibulocochlear - Function

Answer 12

• Balance
• Hearing

Question 13

CN IV - Trochlear - Function

Answer 13

• Eye movement (depression of adducted eye)

Question 14

CN X - Vagus - Function (Sensory)

Answer 14

• sensation to palate, pharynx, larynx, trachea, lungs, epiglottis
• Recurrent Laryngeal Nerve (RLN): sensation below true vocal cords
• Superior Laryngeal Nerve (SLN): posterior tongue and larynx above true vocal cords