Zhu: Regulation of Respiration

Question 1

What are the stimuli for the feedback loop?

Answer 1

increase in arterial PCO2
increase in arterial H+
decrease in arterial PO2 and pH

Question 2

What are the location and effectors of the respiratory control centers?

Answer 2

medulla and pons; respiratory muscles

Question 3

What are the three main respiratory control centers?

Answer 3

Medullary Respiratory Center, Pneumotaxic Center, and Apneustic Center

Question 4

Describe the two main groups of the Medullary Respiratory Center.

Answer 4

1. Dorsal Respiratory Group: ACTIVE inspiration. instrinsic periodic firing/automiaticity; responsible for the basic rhythm of ventilation
2. Ventral Respiratory Group: passive expiration. (not active but can become active if DRG is overstimulated)

Question 5

How is respiratory rate and volume regulated?

Answer 5

Pneumotaxic center: inhibitory effect on the DRG (“switch off”)

(Apneustic Center in animals has shown to have an excitatory effect pm DRG -> prolonged inspiratory gasps. seen in brain injury.)

Question 6

What is the congenital syndrome of respiratory failure during sleep?

Answer 6

Congenital Central Hypoventilation Syndrome/Ondine’s Curse

Question 7

How do central chemoreceptors respond to changes in ECF/CSF?

Answer 7

**Central Chemoreceptors are NOT part of the respiratory control centers. STIMULATED by increase in H+ in ECF/CSF.
(a chance in blood PCO2 will cause this because CO2 can cross the BBB where it combines with H2O->H2CO3- ->HCO3- + H+…….H+ is ultimately the stimulus that is the result of a change in CO2.

Question 8

Ventilatory responses to different stimuli:
Increased arterial PCO2 - which receptor responds?
Decreased pH - which receptor responds?

Answer 8

increased PCO2: C for Central Chemoreceptors

decreased pH, decreased O2: p for Peripheral chemoreceptors

Question 9

What is the Hering-Breuer Inflation Reflex?

Answer 9

when you breathe out air to prevent over-inflation