CH14: Cranial nerves 3

Question 1

sensory fibers of CN IX (glossopharyngeal)

Answer 1

• soft palate
• pharynx
• taste receptors in posterior tongue

Question 2

glossopharyngeal nerve autonomic innervation?

Answer 2

Autonomic afferents from the carotid sinus signal blood pressure spikes in the carotid artery.

Question 3

motor fibers of CN IX innervate:

Answer 3

• pharyngeal muscle

- parotid salivary gland

Question 4

reflexes mediated by glossopharyngeal nerve

Answer 4

• gag

- swallowing

Question 5

What is the gag reflex?

Answer 5

Pharyngeal muscles contracts when pharynx is touched

Question 6

What is the swallowing reflex?

Answer 6

Soft palate moves and pharyngeal muscles contracts when food touches entrance of pharynx

Question 7

Far-reaching connections allow the vagus nerve to:

Answer 7

• decrease HR
• constrict bronchi
• affect speech production
• increase digestive activity

Question 8

How can motor function of the vagus nerve be tested?

Answer 8

eliciting the gag reflex

Question 9

gag reflex

• afferent
• efferent

Answer 9

• glossopharyngeal

- vagus

Question 10

swallowing reflex

• afferent
• efferent

Answer 10

• glossopharyngeal

- vagus

Question 11

The vagus nerve provides afferent and efferent innervation to

Answer 11

• larynx
• pharynx
• viscera

Question 12

The vagus nerve produces (sympathetic/parasympathetic) activity

Answer 12

parasympathetic

Question 13

Where are parasympathetic fibers of the vagus nerve distributed?

Answer 13

• larynx
• pharynx
• trachea
• lungs
• heart
• GI tract (minus large intestine)
• pancreas
• gallbladder
• liver

Question 14

vagus nerve: location of afferent cell bodies

Answer 14

inferior nucleus of the vagus (outside the brainstem)

Question 15

vagus nerve: location of efferent cell bodies

Answer 15

• nucleus ambiguous
• dorsal motor nucleus of vagus

(both in the medulla)

Question 16

CN XI provides motor to

Answer 16

• trapezius

- SCM

Question 17

path of CN XI

Answer 17

• originates in spinal accessory nucleus in upper cervical cord
• travels through foramen magnum
• leaves skull

Question 18

CN XI leaves the skull through the

Answer 18

jugular foramen

Question 19

cell bodies of CN XI are located here

Answer 19

ventral horn (C1-4)

Question 20

CN XII provides motor to

Answer 20

intrinsic and extrinsic muscles of the ipsilateral tongue

Question 21

CN XII cell body locations

Answer 21

hypoglossal nucleus of medulla

Question 22

What is activity of CN XII controlled by?

Answer 22

voluntary and reflexive neural circuits

Question 23

3 stages of swallowing

Answer 23

• oral
• pharyngeal/laryngeal
• esophageal

Question 24

CNs involved in oral stage of swallowing

Answer 24

5
7
9
10
12

Question 25

CNs involved in pharyngeal/laryngeal stage of swallowing

Answer 25

9 | 10

Question 26

CNs involved in esophageal stage of swallowing

Answer 26

10

Question 27

CNs involved in speaking

Answer 27

5 7 10 12

Question 28

Sounds are generated by the

Answer 28

larynx

Question 29

At the CN level, sounds generated by the larynx (CN _) are articulated by these

Answer 29

X - soft palate (X) - lips (VII) - jaws (V) - tongue (XII)

Question 30

Which CNs contain LMN fibers?

Answer 30

3-7 | 9-12

Question 31

How is activity of motor fibers in CNs controlled?

Answer 31

- through descending inputs from voluntary and limbic structures of the brainstem and cerebrum - also via local reflex mechanisms

Question 32

CN efferents receive descending regulation from

Answer 32

- corticofugal tracts | - limbic system

Question 33

Descending limbic pathways and corticobulbar tract relationship (together/separate)

Answer 33

separate

Question 34

descending control of eye movements

Answer 34

- voluntary | - automatic

Question 35

descending control of speaking

Answer 35

mostly voluntary, but can occur automatically in highly emotional contexts

Question 36

What may be preserved in instances in which brain damage interferes with voluntary speech?

Answer 36

ability of the limbic system to produce emotionally charged (i.e. profanity)

Question 37

How do extreme emotions interfere with the ability to eat and speak?

Answer 37

activating limbic pathways that influence motor activity