CN IX - XII

Question 1

CN IX: glossopharyngeal nerve MOTOR fx

Answer 1

stylopharyngeus muscle
-elevates pharynx during swallowing and speaking

Fibers arise form NUCLEUS AMBIGUUS in medulla

Question 2

CN IX: glossopharyngeal nerve PARASYMPATHETIC fx

Answer 2

Parotid gland - largest salivary gland

Preganglionic arise from inferior salivatory nucleus in pons—>travel w/ tympanic n and lesser petrosal nerve —>synapse in octic ganglion providing postganglionics to parotid glands

Question 3

CN IX: glossopharyngeal nerve SENSORY fx (touch pain temp)

Answer 3

Touch pain and temp:
Posterior 1/3 of tongue, upper pharynx and soft palate
Middle ear
Small region of skin near external auditory meatus

Primary sensory neurons to superior and inferior glossopharyngeal ganglion
Synapse in spinal trigeminal nucleus and ascends to PSC

Question 4

CN IX exits

Answer 4

As several rootlets along upper and lateral medulla - just below pontomedullary junction and CNIII

Travels through subarachnoid space to exit at jugular foramen

Question 5

CN IX: glossopharyngeal nerve SENSORY fx (taste)

Answer 5

Posterior 1/3 of tongue
Ascends to roster all nucleus solitaries in medulla
Ascends to taste area of cortex

Question 6

CN IX: glossopharyngeal nerve SENSORY fx (carotid body)

Answer 6

Chemoreceptors and baroreceptors

Ascend to caudal nucleus solitaries in medulla

Question 7

CN X: vagus MOTOR fx

Answer 7

Pharyngeal and upper esophageal muscles (swallowing)

Laryngeal muscles (speaking)

Motor fibers arise from nucleus ambiguus in medulla

Question 8

Unilateral lesion of CN x

Answer 8

Difficulty swallowing and hoarseness

Question 9

CN X: pharyngeal muscles and lesion

Answer 9

Soft palate elevation
W/ lesion - asymmetric elevation

(soft palate lower on side of lesion - uvula will deviate toward normal side)

Question 10

NC X: parasympathetic

Answer 10

Heart, lungs, digestive tract

Largest part of CN X

Preganglionic arise in dorsal nucleus of CN X in medulla
Synapse in terminal ganglia w/in or near target organs

Question 11

CN X sensory touch, pain, temp

Answer 11

Lower pharynx
Larynx
Meninges (dura of post fossa)
Small region of skin near external auditory meatus

Primary sensory neurons ascend to inferior vagal and superior vagal ganglion
Synapse in spinal trigeminal nucleus and ascend to PSC

Question 12

CN X sensory - taste

Answer 12

Epiglottis and posterior pharynx

Ascends in upper nucleus solitaries in medulla

Ascends to taste area of cortex

Question 13

CN X sensory aortic arch

Answer 13

Conveys input from aortic arch and thoracoabdominal viscera
-chemo and baro- receptors
Ascends to lower nucleus solitarius in medulla

Question 14

CN XI motor fx

Answer 14

SCM - turns head to opposite side

UT - elevates shoulder

Question 15

Spinal accessory nuclues sends odor axons

Answer 15

out of the gray matter of spinal cord which exit between the ventral and dorsal roots of the upper five segments of cervical spinal cord

Ascends through foramen magnum to the intracranial cavity

Descends through jugular foramen

Question 16

CN XI lesions

Answer 16

SCM: weakness turning head toward opposite the lesion

UT: ipsilateral weakness of shoulder shrug

Question 17

CN XI UMN lesion

Answer 17

SCM: descends to ipsilateral CN XI nuclues so weakness turning head to opposite side

UT: descend to contralteral CN XI nucleus weakness of opposite shoulder shrug

Question 18

CN XII hypoglossal

Motor

Answer 18

Intrinsic and extrinsic muscles of tongue

Rootlets exit ventral medulla b/n pyramid and olive to travel through hypoglossal foramen

Question 19

Hypoglossal nucleus

Answer 19

Midline on the floor of 4th ventricle in medulla

Question 20

CN XII UMN lesion

Answer 20

From tongue area of PCM travel w/ corticobulbar tract to synapse on contralateral CN XII nuclei

Ipsilateral lesion of PMC or UMN of CB tract will cause contralateral tongue weakness

Question 21

CN XII LMN lesion

Answer 21

Ipsilateral lesion to CN XII nucleus or nerve fibers will cause ipsilateral tongue weakness
Tongue will deviate toward weak side (side of lesion)

Question 22

Dysarthria

Answer 22

Abnormal articulation of speech
• Motor articulatory disorder
• Can range from mild to unintelligible speech
• Can occur with dysfunction of muscles of articulation (jaw,
lips, pharynx, and tongue), NM junction, or peripheral or central portions of CN V, VII, IX, X, or XII
• Can have many other causes: dysfunction of PMC face area,
cerebellum, basal ganglia, or descending corticobulbar fibers

Question 23

Common causes of dysarthria

Answer 23

CVA, MS, ALS, MG, ETOH, any other

muscular disorders

Question 24

Dysphasia

Answer 24

Impaired swallowing
• Can lead to aspiration of food, choking, and esophageal
reflux can lead to aspiration of gastric secretions
• Caused by esophageal strictures, neoplasms, local lesions, or
neural or neuromechanical basis
• Can occur with dysfunction of CN V, VII, IX, X, or XII
• Can have the same cause(s) as dysarthria, and they can
occur together

Question 25

Aspiration pneumonia

Answer 25

Caused by impaired swallowing function
• Difficult to treat
• Common cause of death

Question 26

Gag reflex

Answer 26

Protective reflex preventing entry of foreign objects into alimentary and respiratory passageways

CN IX (sensory component) and CN X (motor component)

Touch posterior pharynx (or soft palate) with cotton-tipped swab, and pharyngeal muscles contract

Question 27

PSEUDOBULBAR AFFECT (PBA)

Answer 27

Uncontrollable bouts of laughter or crying without any appropriate emotional reasons
• Brainstem nuclei involved in laughing and crying include
CN VII, IX, X, and XII

Question 28

Lesions of corticobulbar pathways or brainstem

Answer 28

Can produce PBA

Question 29

Common cause of PBA

Answer 29

CVA
MS
ALD
AD
TBI
Tumors
Etc