Week 13 Cranial Nerves

Question 1

CN I

• Name
• Where does it exit the skull?
• Primary Function?

Answer 1

• CN 1: Olfactory Nerve
• Passes through cribiform plate
• Sensory: Smell

Question 2

CN II

• Name
• Where does it exit the skull?
• Primary function?

Answer 2

• CN II: Optic Nerve
• Exits via optic canal.
• Sensory: Vision

Question 3

CN III

• Name
• Where does it exit the skull?
• Primary functions?

Answer 3

-CN III: Oculomotor Nerve
-Exits via superior orbital fissure
-Motor: extra ocular eye muscles
Parasympathetics to the Ciliary ganglion

Question 4

CN IV

• Name
• Where does it exit the skull?
• Primary function?

Answer 4

• CN IV: Trochlear Nerve
• Exits via superior orbital fissure.
• Motor: Superior oblique muscle of the eye.

Question 5

CN V

• Name
• Division branches
• General Functions
• Where does each branch exit the skull?
• Primary functions?

Answer 5

-CN V: Trigeminal Nerve
-Opthalmic (CN V1), Maxillary (CN V2), Mandibular (CN V3).
-Fxns:
Sensory to the face, sinuses, nasopharynx, and oral cavity.
Motor to the muscles of mastication by V3
Postsynaptic autonomics to target organs

Question 6

CN VI

• Name
• Where does it exit the skull?
• Primary function?

Answer 6

• CN VI: Abducent nerve
• Exits via superior orbital fissure.
• Motor: Lateral Rectus muscle of the eye.

Question 7

CN VII

• Name
• Where does it exit the skull?
• Branches?
• Primary functions?

Answer 7

-CN VII: Facial nerve
-Exits via Stylomastoid foramen
-Branches: Temporal, Zygomatic, Buccal, Marginal mandibular, Cervical. And posterior auricular nerve.
-Fxns:
Sensation of taste to anterior 2/3 of tongue via Chorda tympani
Motor to muscles of facial expression plus Stapeuis, Stylohyoid, and Posterior belly of the digastric
Parasympathetics to lacrimal and mucosa via Greater petrosal nerve and pterygopalatine ganglia. Parasympathetics to sublingual and submandibular gland via chorda tympani.

Question 8

CN VIII

• Name
• Where does it exit the skull?
• Primary function?

Answer 8

• CN VIII Vestibulocochlear
• Exits via internal acoustic meatus
• Fxn: Cochlear for hearing. Vestibular for proprioception.

Question 9

CN IX:

• Name
• Where does it exit the skull?
• Primary Functions?

Answer 9

-Cn IX: Glossopharyngeal
-Exits via jugular foramen.
-Fxns
Sensory to pharyngeal plexus, tonsils, and tympanic plexus (auditory tube, tympaic cavity). Taste and Sensation to posterior 1/3 of tongue. Chemoreceptor axons to carotid sinus with CN X.
Motor to stylopharyngeus (pharynx muscle)
Parasympathetics to the Parotid gland. (tympanic–> tympanic plexus–> lesser petrosal–> otic ganglia–> auriculotemporal (V3)

Question 10

CN X:

• Name
• Branches in this region?
• Where does it exit the skull?
• Primary functions?

Answer 10

-CN X: Vagus
-Exits via Jugular foramen
-Pharyngeal, Superior Laryngeal (Internal and External Branches), Inferior Laryngeal.
-Fxns
Sensation to posterior dura, external ear, and larynx
Motor to pharyngeal plexus and soft palate. Motor to laryngeal muscles (speech)
Parasympathetics to much of trunk and abdomen.

Question 11

CN XI:

• Name
• Where does it exit the skull?
• Primary function

Answer 11

• CN XI: Spinal Accessory
• Travels up through foramen magnum and then out via the jugular foramen.
• Fxn: Motor to sternocleidomastoid and trapezius. Also sends a branch to join CN X motor component of pharyngeal plexus.

Question 12

CN XII

• Name
• Where does it exit the skull?
• Primary function?

Answer 12

• CN XII: Hypoglossal
• Exits via hypoglossal canal
• Motor to intrinsic and extrnisic muscles of the tongue (except palatoglossus (CN X)