Pulmonary Circulation & Exercise

Question 1

what is the systolic pressure in a pulmonary artery?

Answer 1

25

Question 2

what is the diastolic pressure in a pulmonary artery?

Answer 2

8

Question 3

what is the systolic pressure in a systemic artery?

Answer 3

120

Question 4

what is the diastolic pressure in a systemic artery?

Answer 4

80

Question 5

what happens to pulmonary capillaries with lack of oxygen?

Answer 5

constrict (lack of O2=lack of blood)

Question 6

what happens to systemic capillaries with lack of oxygen?

Answer 6

dilation

Question 7

zone 1

Answer 7

no blood flow, highest alveolar pressure

Question 8

zone 2

Answer 8

• intermediate region
• blood flows only in systole

Question 9

zone 3

Answer 9

• region closest to base of lung
• continuous blood flow

Question 10

blood flow in zone 1 is usually ____

Answer 10

pathological

Question 11

blood flow in zone 2 is normal…

Answer 11

in the apex of lungs when upright

Question 12

blood flow in zone 3 is normal…

Answer 12

in lower lung when upright

Question 13

when does continuous pulmonary blood flow occur?

Answer 13

• normally in lower lung when upright
• entire lung when lying down or exercising

Question 14

increased blood flow during exercise is due to…

Answer 14

recruitment & distention

Question 15

during exercise, what happens to O2 levels?

Answer 15

• less O2 in lungs
• increased ventilation/perfusion ratio
• O2 levels remain normal

Question 16

during exercise, what happens to CO2 levels?

Answer 16

• CO2 initially increases
• increased rate of ventilation returns CO2 levels to normal almost immediately

Question 17

how does one become a better breather?

Answer 17

learned behavior in the brain (swimmers are good breathers)

Question 18

at rest, describe the ventilation of the upper, middle, and lower lung zones from lowest to highest

Answer 18

upper (1) = lowest
middle (2) = intermediate
lower (3) = highest

Question 19

describe the differences in flow, resistance, and arterial pressure in pulmonary circulation compared to systemic circulation

Answer 19

flow = same
resistance = lower
arterial P = lower

Question 20

if a bronchiole is blocked by food, what changes occur to:
a) left lung alveolar PCO2
b) left lung alveolar PO2
c) systemic arterial PO2

Answer 20

a) increase
b) decrease
c) decrease

Question 21

describe the changes in arterial PO2, arterial PCO2, and arterial pH that occur in a healthy athlete during strenuous exercise

Answer 21

all remain the same

Question 22

during exercise, what happens to lung-diffusing capacity and why?

Answer 22

increases because blood flow is continuous in all pulmonary capillaries during exercise

Question 23

when cardiac output increases to a maximum, what happens to the pulmonary vasculature?

Answer 23

• pulmonary blood flow increases
• vessels enlarge (distension)
• recruitment & distension of pulmonary vessels lowers pulmonary vasculature resistance and maintains low pulmonary BP