Cranial Nerves

Question 1

I. Olfactory

Answer 1

Sensory.
Origin = Olfactory bulb Function(s) = Smell

Question 2

II. Optic

Answer 2

Sensory.
Origin= Thalamus
Function= Vision

Question 3

III. Oculomotor

Answer 3

Motor.
Origin=Midbrain
Function= moves eyes left+right, control eyelids, pupil constrictor

Question 4

IV. Trochlear

Answer 4

Motor.
Origin=Midbrain
Functions= Moves eyes up and down.

Question 5

V. Trigeminal

Answer 5

Sensory and Motor (B).
Origin= Pons
Function= Ophthalmic branch; sensory info from upper face, forehead, scalp to CNS. Maxillary branch; sensory info from teeth, upper lip, buccal, nasal cavities, sides of face to CNS. Mandibular; sensory info from lower teeth, lower gums, bottom lips, and portions of the tongue to CNS. Motor info to muscles for mastication.

Question 6

VI. Abducens

Answer 6

Motor.
Origin= Pons
Function= Rotates eyes out.

Question 7

VII. Facial

Answer 7

Sensory and motor (B).
Origin= Pons
Functions= Motor info to the face. Sensory info from the anterior ⅔ of tongue. Temporal + zygomatic branches; motor info to muscles of upper face, bilaterally innervated. Buccal - Mandibular branches; motor info to muscles of the lower face. Unilaterally innervated.

Question 8

VIII. Vestibulocochlear/Auditory

Answer 8

Sensory.
Origin= Pons/Medulla junction.
Functions = hearing and balance.

Question 9

IX. Glossopharyngeal

Answer 9

Sensory and motor (B).
Origin= Pons/medulla junction
Function(s) = Pharyngeal movement, salivation, Middle ear, pharynx, post. 1/3 of tongue, Taste on post. 1/3 of tongue

Question 10

X. Vagus

Answer 10

Sensory and motor (B).
Origin = Medulla Function(s)=Innervated soft palate, pharyngeal and laryngeal muscles. Pharyngeal plexus innervates the portion of pharynx for swallowing and elevates velum for non nasal sounds. Superior Laryngeal Nerve (SLN) sends afferent info from inside larynx to CNS (Intrinsic branch), Innervated cricothyroid muscle (Extrinsic branch) Recurrent laryngeal nerve: (RLN) Right RLN passes under right subclavian artery, left RLN passes under arch of aorta, both recur into neck/larynx and innervate muscles for adduction/abduction of vocal folds.

Question 11

XI. Spinal Accessory

Answer 11

Motor.
Origin = Medulla, spinal cord Function(s) = cranial component works as an accessory of vagus, spinal component innervates muscles of the shoulders

Question 12

XII. Hypoglossal

Answer 12

Motor.
Origin = Medulla Function(s) = Innervates all intrinsic muscles of the tongue, fine motor movements of the tongue, innervates most extrinsic muscles of the tongue, gross motor movements of tongue.