CN X-XII

Question 1

Name CN X

Answer 1

Vagus

Question 2

CN X vagus origins and levels (4)

Answer 2

1. Dorsal motor nucleus (parasympathetic) at medulla
2. nucleus abiguus (motor) at medulla
3. nucleus of solitary tract (taste and parasympathetic) at medulla
4. nucleus of spinal tract of trigeminal (sensory) at medulla

Question 3

Where does CN X vagus exit?

Answer 3

Post-olivary sulcus

Question 4

Parasympathetic function of CN X vagus

Answer 4

Parasympathetic to thorax and abdomen

Question 5

Motor function of CN X vagus

Answer 5

Motor to pharyngeal constrictors, intrinsic laryngeal muscles, palatine muscles (except tensor veli palatini), and upper esophagus for phonation and swallowing

Question 6

Taste function of CN X vagus

Answer 6

Taste fibers from larynx and epiglottis

Question 7

Sensory function of CN X vagus

Answer 7

Sensory to the pharynx, larynx, concha of external ear, and meninges of posterior fossa

Question 8

CN X vagus lesion

Answer 8

Hoarseness, dysphagia, loss of gag reflex, and uvular deviation to the strong side

Question 9

Where does CN X vagus exit the skull?

Answer 9

Jugular foramen

Question 10

CN XI name

Answer 10

Accessory

Question 11

CN XI accessory origin and level

Answer 11

Nucleus ambiguus and disperse cell bodies at medulla and cervical segments

Question 12

Where does CN XI accessory exit?

Answer 12

Post-olivary sulcus

Question 13

What branches does CN XI accessory split into?

Answer 13

Cranial and spinal roots

Question 14

Cranial root of CN XI accessory function

Answer 14

Joins the vagus nerve to supply the muscles of the pharynx, larynx, and soft palate

Question 15

Spinal root of CN XI accessory function

Answer 15

Motor to SCM and trapezius muscles

Question 16

CN XI accessory lesion

Answer 16

Inability to rotate head and shrug shoulders

Question 17

Where does CN XI accessory exit the skull?

Answer 17

Jugular foramen

Question 18

CN XII name

Answer 18

Hypoglossal

Question 19

CN XII hypoglossal origin and level

Answer 19

Hypoglossal nucleus at medulla

Question 20

Where does CN XII hypoglossal exit?

Answer 20

Pre-olivary sulcus

Question 21

Function of CN XI hypoglossal

Answer 21

Motor to all tongue muscles except palatoglossus which is supplied by the vagus like all palatine muscles

Question 22

CN XII hypoglossal lesion

Answer 22

Ipsilateral tongue paralysis and atrophy

Question 23

Where does CN XII hypoglossal exit the skull?

Answer 23

Hypoglossal canal

Question 24

Supranuclear (UMN) symptoms of CNs are rare (except for CN VII facial) because…

Answer 24

corticobulbar tract innervates most of them bilaterally