CH14: Cranial nerves 3 Flashcards Preview

7303 Neuroanatomy > CH14: Cranial nerves 3 > Flashcards

Flashcards in CH14: Cranial nerves 3 Deck (37):
1

sensory fibers of CN IX (glossopharyngeal)

- soft palate
- pharynx
- taste receptors in posterior tongue

2

glossopharyngeal nerve autonomic innervation?

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

3

motor fibers of CN IX innervate:

- pharyngeal muscle
- parotid salivary gland

4

reflexes mediated by glossopharyngeal nerve

- gag
- swallowing

5

What is the gag reflex?

Pharyngeal muscles contracts when pharynx is touched

6

What is the swallowing reflex?

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

7

Far-reaching connections allow the vagus nerve to:

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

8

How can motor function of the vagus nerve be tested?

eliciting the gag reflex

9

gag reflex
- afferent
- efferent

- glossopharyngeal
- vagus

10

swallowing reflex
- afferent
- efferent

- glossopharyngeal
- vagus

11

The vagus nerve provides afferent and efferent innervation to

- larynx
- pharynx
- viscera

12

The vagus nerve produces (sympathetic/parasympathetic) activity

parasympathetic

13

Where are parasympathetic fibers of the vagus nerve distributed?

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

14

vagus nerve: location of afferent cell bodies

inferior nucleus of the vagus (outside the brainstem)

15

vagus nerve: location of efferent cell bodies

- nucleus ambiguous
- dorsal motor nucleus of vagus

(both in the medulla)

16

CN XI provides motor to

- trapezius
- SCM

17

path of CN XI

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

18

CN XI leaves the skull through the

jugular foramen

19

cell bodies of CN XI are located here

ventral horn (C1-4)

20

CN XII provides motor to

intrinsic and extrinsic muscles of the ipsilateral tongue

21

CN XII cell body locations

hypoglossal nucleus of medulla

22

What is activity of CN XII controlled by?

voluntary and reflexive neural circuits

23

3 stages of swallowing

- oral
- pharyngeal/laryngeal
- esophageal

24

CNs involved in oral stage of swallowing

5
7
9
10
12

25

CNs involved in pharyngeal/laryngeal stage of swallowing

9
10

26

CNs involved in esophageal stage of swallowing

10

27

CNs involved in speaking

5
7
10
12

28

Sounds are generated by the

larynx

29

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

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

30

Which CNs contain LMN fibers?

3-7
9-12

31

How is activity of motor fibers in CNs controlled?

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

32

CN efferents receive descending regulation from

- corticofugal tracts
- limbic system

33

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

separate

34

descending control of eye movements

- voluntary
- automatic

35

descending control of speaking

mostly voluntary, but can occur automatically in highly emotional contexts

36

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

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

37

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

activating limbic pathways that influence motor activity