Glossopharyngeal Nerve

Question 1

Is the glossopharyngeal nerve a mixed, sensory or motor nerve?

Answer 1

Mixed nerve with both sensory and motor components

Question 2

What are the 3 types of sensory fibers for the glossopharyngeal nerve?

Answer 2

Somatosensory neurons
Gustatory neurons
General Visceral Afferent neuons

Question 3

Where are the cell bodies of primary somatosensory neurons of the glossopharyngeal nerve located?

Answer 3

Superior ganglion of IX nerve

Question 4

Where are the peripheral processes of somatosensory neurons of glossopharyngeal nerve distributed?

Answer 4

Posterior 1/3 of tongue
Upper Pharynx
Tympanic Cavity
Eustachian tube

Question 5

Where do the central processes of the somatosensory neurons of the glossopharyngeal nerve enter and terminate?

Answer 5

Enter brainstem, joins the spinal tract of the trigeminal nerve and terminate in the spinal trigeminal nucleus (2nd order neurons

Question 6

Where do somatosensory neurons of the glossopharyngeal nerve travel from the spinal trigeminal nucleus?

Answer 6

Ascend to the VPM nucleus of the thalamus through the trigeminothalamic tract

Question 7

Where do somatosensory neurons of the glossopharyngeal nerve travel from the spinal trigeminal nucleus?

Answer 7

Third order neurons of the VPM nucleus project axons through the posterior limb of the internal capsule and terminate in primary somatosensory cortex

Question 8

What are somatosensory afferents of the glossopharyngeal nerve serve as in regards to the gag reflex?

Answer 8

The afferent limb of the gag reflex (response that occurs to touching posterior 1/3 of tongue or upper pharynx

Question 9

What does the efferent limb of the gag reflex innervated by?

Answer 9

X nerve - palate and pharynx muslces
XII nerve - tongue uscles
V nerve - mastication

Question 10

Where are the cell bodies of primary gustatory neurons of the glossopharyngeal nerve located?

Answer 10

Primary neurons cell bodies are found in the inferior ganglion of the IX nerve

Question 11

Where are the peripheral processes of Gustatory neurons of glossopharyngeal nerve distributed?

Answer 11

Peripheral processes distributed through ligual branches of IX nerve to the posterior 1/3 of the tongue

Question 12

Where do the central processes of the gustatory neurons of the glossopharyngeal nerve enter and terminate?

Answer 12

Central processes enter brainstem and terminate in the solitary nucleus (rostral part in the medulla

Question 13

Where do gustatory neurons of the glossopharyngeal nerve travel from the solitary nucleus?

Answer 13

Fibers of the second order neurons ascend the brainstem through the ipsilateral central tegmental tract to terminate in the VPM nucleus of the thalamus

Question 14

Where do gustatory neurons of the gloospharyngeal nerve poject axons of taste area?

Answer 14

Thalamic neurons project axns to the “taste area of the cerebral cortex located in the parietal lobe and insula

Question 15

Where are the cell bodies of General Visceral neurons of the glossopharyngeal nerve located?

Answer 15

Cell bodies in the inferior ganglion of IX nerve

Question 16

Where are the peripheral processes of General Visceral afferent neurons of glossopharyngeal nerve distributed?

Answer 16

To the carotid sinus (barception) and carotid body (chemoreception)

Question 17

Where do the central processes of the General Visceral afferent neurons of the glossopharyngeal nerve enter and terminate?

Answer 17

Enter brainstem in IX nerve and descend in the medulla in the solitary tract and terminate in the solitary nucleus (caudal part)

Question 18

What are the two motor components of the glossopharyngeal nerve?

Answer 18

Lower Motor Neurons

Autonomic

Question 19

Where are the cell bodies of the somatomotor neurons of glossopharyngeal nerve found?

Answer 19

Ambiguosia medulla

Question 20

What do the the somatomotor neurons of glossopharyngeal nerve innervate?

Answer 20

Stylopharyngeus

Question 21

Will there be paralysis of the stylopharygeus muscle with a upper motor neuron lesion?

Answer 21

No paralysis of stylopharyngeus because the motor components receive bilateral corticobulbar innervation

Question 22

Where are the parasympathetic neuron cell bodies of the glossopharyngeal nerve found?

Answer 22

Cell bodies comprise the inferior salivatory nucleus located in the medulla

Question 23

Where do parasympathetic neurons of the glossopharygeal nerve terminate?

Answer 23

Fibers terminate in the otic ganglion (postganglionic parasympathetic)

Question 24

Where do the postganglionic fibers of the glossopharyngeal nerve provide secretomotor innervation to?

Answer 24

Parotid gland

Question 25

What occurs when a unilateral lesion of the IX nerve happens?

Answer 25

Loss of gag reflex on ipsilateral side
Decreased taste sensation from the ipsilateral 1/3 of tongue
Decreased salivation