Lecture 16 - Respiratory Control Physiology

Question 1

The _____ and the _____ are the main drivers of CNS control of breathing. Specifically, the _____ is responsible for controlling INSPIRATION and the _____ is responsible for controlling EXPIRATION (mostly).

Answer 1

Pons and Medulla

DRG (Dorsal Respiratory Group)

VRG (Ventral Respiratory Group)

Question 2

The _______ center of the Pons sends INHIBITORY signals to the DRG. Increased activity in this center ______ (increases or decreases?) inhalation time. Conversely, the ______ center STIMULATES the DRG and VRG, causing _______ (longer or shorter?), ______ (more shallow or deeper?) breaths.

Answer 2

Pneumotaxic Center

Decreases

Apneustic Center

Longer

Deeper

Question 3

What is the Hering-Breuer inflation reflex?

Answer 3

It is a reflex that occurs at very large tidal volumes (Vt of about 1000mL) that inhibits the inspiratory center (DRG) –> slows respiration frequency

Question 4

Peripheral chemoreceptors are located in the _____ and _____ bodies. They primarily respond to low _____ and ______ respiration accordingly.

Answer 4

Carotid and Aortic bodies

Low pO2

Increase

Question 5

Central Chemoreceptors responds mostly to changes in _____ secondary to changes in CO2.

Answer 5

H+

Question 6

Chemoreceptors responding to changes in _____ are more active in their response than Chemoreceptors that respond to changes in _____. That said, changes in O2 increase the degree of response from pCO2 chemoreceptors and changes in CO2 increase the degree of response from pO2 cemoreceptors.

Answer 6

pCO2

pO2

Question 7

Why is the initial response to changes in pH mediated almost entirely by Peripheral Chemoreceptors?

Answer 7

Becuase H+ can not readily cross the BBB.

Question 8

Cheyne-Stokes respiration can be seen in patients with _____, _____ _____ (bc of low ejection fraction), or those at high ______. It is characterized by periods of Tachypnea followed by Apnea.

Answer 8

BI

Heart Failure

High Altitude

Question 9

_____ Curse is a Congenital Hypoventilation syndrome in which most patients hypoventilate during sleep. There is a dysfunction of ______ control of breathing, so these patients rely on afferent signals from _____ receptors. These patients should be treated with Nighttime ventilatory support and diaphragm pacing.

Answer 9

Ondine’s Curse

Metabolic control

Mechanoreceptors

Question 10

pO2 chemoreceptors typically do not respond until PaO2 is < ______ mmHG.

Answer 10

60mmHg