Regulation of Respiratory System I/II Flashcards Preview

CVRH Exam 3 > Regulation of Respiratory System I/II > Flashcards

Flashcards in Regulation of Respiratory System I/II Deck (25)
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1
Q

Where is a cycle of inspiration and expiration automatically generated?

A

In the CNS central pattern generator (CPG)

2
Q

What drives the CPG?

A

Chemoreceptors (both central and peripheral) sensing PO2, PCO2 and pH

3
Q

What does the CPG regulate specifically?

A

Respiratory muscles, most importantly the diaphragm

4
Q

What is eupnea?

A

Quiet, normal, easy breathing

5
Q

What does negative feedback on the CPG come from?

A

An increase in alveolar ventilation

6
Q

How is the CPG affected b higher center respiratory motor activity?

A

They send inputs to the CPG during intense exercise

7
Q

Where is the central pattern generator located?

A

Ventrolateral medulla oblongata

8
Q

What does the pons do in respiration?

A

It only modulates respiratory output but is not necessary for respiratory output itself

9
Q

What is the dorsal respiratory group (DRG)?

A

Has sensory input and contains primarily inspiratory neurons

10
Q

Where are the DRG found?

A

Nucleus of solitary tract in the medulla

11
Q

What is the ventral respiratory group (VRG)?

A

Primarily motor and contains both inspiratory and expiratory neurons

12
Q

What is the CPG composed of?

A

DRG and VRG

13
Q

What center can terminate inspiration?

A

Pontine apneustic center

14
Q

What modulates the apneustic center and fine tunes respiration?

A

Pneumotaxic center

15
Q

What do peripheral chemoreceptors respond to?

A

Primarily sensitive to decreasing PO2 less so to increase in PCO2 and decreased pH

16
Q

What are central chemoreceptors sensitive to?

A

Increase in arterial PCO2 (H+)

17
Q

What generates the respiratory rhythm?

A

Pacemaker neurons or synaptic interactions within the CPG

18
Q

What is the chemosensor in the carotids and aortic bodies?

A

Glomus cell

19
Q

What does acidosis cause in the carotid chemosensors?

A

Makes it more sensitive to arterial PCO2

20
Q

What occurs when PaCO2 goes from 40 to 45 mmHg?

A

Ventilation will double

21
Q

How does the central chemoreceptor respond to CO2 and H+?

A

CO2 can cross BBB but H+ cannot therefore the brain responds to local acidosis

22
Q

What stimulates ventilation more hypoxia or respiratory acidosis?

A

Respiratory acidosis

23
Q

What do juxtacapillary (J receptors) do?

A

Sense mechanical or chemical irritants and elicit rapid and shallow breathing, bronchoconstriction and mucous secretion as a defense mechanism

24
Q

What do the slowly-adapting pulmonary stretch mechanoreceptors (PSR) do?

A

Detect lung volume and inhibit the medullary output to phrenic motor neurons producing Hering-Breuer Reflex

25
Q

What does the Hering-Breuer reflex do?

A

Stops over-inflation of the lungs