Medullary Reflexes Flashcards Preview

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Flashcards in Medullary Reflexes Deck (24):
1

What 2 centers control respiration?

- Apneustic center
- Pneumotaxic center

2

Where is the pneumotaxic center found?

In the pons

3

Where is the apneustic center found?

In the medulla

4

Which respiratory center sends stimulation to the inspiratory area?

Apneunstic

5

Which respiratory center inhibits the inspiratory area?

Pneumotaxic

6

Which respiratory center causes long deep breaths?

Apneustic

7

Which respiratory center fine tunes respiration?

Pneumotaxic

8

How do the respiratory groups in the medulla reach somatic innervation in the body, how does the body communicate back?

- Reticular spinal tracts go to the cervical cord
- Travel by the phrenic nerve to diaphragm and intercostal muscles
- Afferents from alveoli through CN X go to the solitary nucleus, which triages input

9

What type of reflex is respiration?

Visceral-somatic

10

Describe the pathway of baroreceptor and chemoreceptor reflexes.

- BP changes/ CO2 changes stimulating baro/chemoreceptor
- Baroreceptors travel up CNs IX or X
- Go to solitary nucleus
- Decrease contractility of heart and blood vessels through the vagal nerve (CN X)

11

What type of reflex is the baro/chemoreceptor reflex?

Visceral-visceral

Vagal-Vagal

12

Describe the pathway of a cough reflex.

- GVA info from the trachea, larynx, or pharynx travel to the nucleus solitarius via CN X
- Solitary nucleus projects to upper respiratory centers to activate pneumotaxic center
- Pneumotaxic center causes forced expiration (at diaphragm, intercostals, and abdominals)
- Nucleus ambiguus contracts larynx and pharynx

13

What initiates vomiting? Where is this structure found?

- Area postrema
- Floor of 4th ventricle

14

How does the area postrema cause vomiting?

- Stimulation of AP triggers reflex
- Signal projects to reticular formation
- Travels down vagus nerve to contract contents of stomac (also relaxing gastroesophageal sphincter)
- Travels down cord to abdominal muscles to contract

15

What type of reflex is the vomit reflex?

Visceral-visceral and visceral-somatic

16

What nerve do the afferents causing the vomiting reflex travel?

CN X

17

What type of reflex is the pupillary reflex?

Somatic-visceral

18

How is pupil dilation changed in the pupillary reflex of the medulla?

Touch/ pain receptors of skin in face

19

What nerve supplies the afferent component of the papillary reflex? What structure do the afferents synapse on?

- CN V
- Reticular formation

20

Describe the efferent component of the pupillary reflex.

- Descends down cord from RF
- Stimulates betacell in lateral horn (Sympathetic)
- Enters superior chain ganglion
- Contracts muscle in eye

21

What type of reflex is the carotid-sinus reflex?

Visceral-visceral

22

What nerve carries the afferent fibers of the carotid-sinus reflex? What structure does it synapse on?

- CN IX
- Reticular formation
- Dorsal motor nucleus of CN X
AND
- Nucleus ambiguus

23

What nerve carries the fibers from the nucleus ambiguus and motor nucleus of CN X to the heart to reduce contractility in the carotid sinus reflex? Where does the nerve synpase?

CN X

- On SA and AV nodes, and atrial muscle

24

What nervous system is used to dilate blood vessels in the carotid-sinus reflex?

Sympathetic