Regulation of Respiration

Question 1

what 3 sensors regulate respiration?

Answer 1

stretch sensors
chemical sensors
irritant receptors

Question 2

where are stretch sensors located?

Answer 2

bronchi walls

Question 3

what is the function of stretch sensors?

Answer 3

inhibits inspiration by Hering-Breuer reflex

Question 4

what is the mechanism of stretch sensors?

Answer 4

• phrenic nerve stimulates diaphragm to contract
• at max inhalation, stretch receptor via vagus inhibits dorsal respiratory group
• inhibits phrenic nerve which inhibits inspiration

Question 5

what are the 2 types of chemical sensors?

Answer 5

central & peripheral

Question 6

where are central chemical sensors located?

Answer 6

in respiratory center

Question 7

what do central chemical sensors respond to?

Answer 7

increased CO2

Question 8

what is the function of central chemical sensors?

Answer 8

increase ventilation by increasing both inspiration & expiration

Question 9

where are peripheral chemical sensors located?

Answer 9

in the carotid bodies

Question 10

what do peripheral chemical sensors respond to?

Answer 10

• decreased O2
• decreased pH (can be increased CO2 due to carbonic acid in RBC)

Question 11

what is the function of peripheral chemical sensors?

Answer 11

increase ventilation

Question 12

what do irritant receptors respond to?

Answer 12

inhaled irritants (smoke, perfume, etc)

Question 13

what is the function of irritant receptors?

Answer 13

cause bronchoconstriction & increased ventilation rate with short, rapid breaths

Question 14

which type of chemical receptor has the greatest impact on ventilation?

Answer 14

central

Question 15

what is the function of the dorsal respiratory group?

Answer 15

controls quiet breathing and inspiration via the inspiratory ramp

Question 16

what is the function of the ventral respiratory group?

Answer 16

extra respiratory drive: forced inspiration & expiration

Question 17

what is the function of the pneumotaxic center?

Answer 17

limits inspiration, increases rate of breathing

Question 18

what is the most important pathway for the respiratory response to systemic arterial CO2 (PCO2)?

Answer 18

H+ activation of the chemosensitive area of the medulla

Question 19

what limits the duration of inspiration and increases respiratory rate?

Answer 19

pneumotaxic center

Question 20

where are the respiratory neurons that become active during increased respiratory drive located?

Answer 20

ventral respiratory group

Question 21

where are the afferent endings for the Hering-Breuer reflex (mechanoreceptors) located?

Answer 21

bronchi & bronchioles

Question 22

when breathing in and out of a bag, what is responsible for the increase in ventilation?

Answer 22

increased alveolar PCO2