resp response to exercise

Question 1

elastic work of breathing _____ during exercise

Answer 1

increases

Question 2

how much does tidal volume (Vt) increase during exercise

Answer 2

5-6 fold

Question 3

airway resistance _____ during exercise, & why

Answer 3

decreases
bc airway diameter increases (bronchodilation)

Question 4

ventilation rate _____ during exercise, & why

Answer 4

increases
bc central & peripheral chemoreceptors respond

Question 5

central chemoreceptors location

Answer 5

ventral surface of medulla

Question 6

peripheral chemoreceptors location

Answer 6

carotid & aortic bodies

Question 7

peripheral chemoreceptors mainly respond to change in _____

Answer 7

oxygen

Question 8

central chemoreceptors mainly respond to change in _____

Answer 8

CO2

Question 9

which chemoreceptor is the “first responder” to changes in ventilation rate, & why

Answer 9

central chemoreceptors
bc they respond faster

Question 10

anatomic dead space _____ during exercise

Answer 10

increases

Question 11

alveolar ventilation rate (Va) equation

Answer 11

Va = (Vt - Vd) x RR

Vt: tidal volume
Vd: dead space volume
RR: breaths per min

Question 12

Vd / Vt ratio _____ during exercise, & why

Answer 12

decreases
bc Vt increases more than Vd

Question 13

pulmonary blood flow:

perfusion of upper lung _____ during exercise

Answer 13

increases

Question 14

pulmonary blood flow:

pulmonary vascular resistance _____ during exercise

Answer 14

decreases

Question 15

pulmonary blood flow:

linear velocity of blood flow _____ during exercise

Answer 15

increases

Question 16

surface area of alveolar-capillary barrier _____ during exercise, & why

Answer 16

increases
bc of high lung volume

Question 17

perfusion limitation of alveolar-capillary barrier _____ during exercise

Answer 17

decreases

Question 18

partial pressure gradient of alveolar-capillary barrier _____ during exercise, & why

Answer 18

increases
bc alveolar-arterial gradient increases

Question 19

V/Q ratio _____ during exercise, & why

Answer 19

increases
bc V increases more than Q

Question 20

oxygen unloading at the tissue _____ during exercise, & why

Answer 20

increases
bc O2-Hb dissociation curve shifts to the right

Question 21

PAO2 _____ during vigorous exercise, & why

Answer 21

increases
bc A-a gradient increases

Question 22

PaO2 _____ during vigorous exercise, & why

Answer 22

decreases
bc A-a gradient increases

Question 23

PACO2 _____ during vigorous exercise, & why

Answer 23

increases
bc PCO2 slightly increases

Question 24

pHa _____ during vigorous exercise, & why

Answer 24

decreases
bc pH slightly decreases

Question 25

CO2 diffuses into blood & is transported via 3 forms:

Answer 25

bicarbonate: 70%
carbaminohemoglobin: 23%
physically dissolve: 7% (contributes to partial pressure)