Pulmonary Circulation & Exercise Flashcards
what is the systolic pressure in a pulmonary artery?
25
what is the diastolic pressure in a pulmonary artery?
8
what is the systolic pressure in a systemic artery?
120
what is the diastolic pressure in a systemic artery?
80
what happens to pulmonary capillaries with lack of oxygen?
constrict (lack of O2=lack of blood)
what happens to systemic capillaries with lack of oxygen?
dilation
zone 1
no blood flow, highest alveolar pressure
zone 2
- intermediate region
- blood flows only in systole
zone 3
- region closest to base of lung
- continuous blood flow
blood flow in zone 1 is usually ____
pathological
blood flow in zone 2 is normal…
in the apex of lungs when upright
blood flow in zone 3 is normal…
in lower lung when upright
when does continuous pulmonary blood flow occur?
- normally in lower lung when upright
- entire lung when lying down or exercising
increased blood flow during exercise is due to…
recruitment & distention
during exercise, what happens to O2 levels?
- less O2 in lungs
- increased ventilation/perfusion ratio
- O2 levels remain normal
during exercise, what happens to CO2 levels?
- CO2 initially increases
- increased rate of ventilation returns CO2 levels to normal almost immediately
how does one become a better breather?
learned behavior in the brain (swimmers are good breathers)
at rest, describe the ventilation of the upper, middle, and lower lung zones from lowest to highest
upper (1) = lowest
middle (2) = intermediate
lower (3) = highest
describe the differences in flow, resistance, and arterial pressure in pulmonary circulation compared to systemic circulation
flow = same
resistance = lower
arterial P = lower
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
a) increase
b) decrease
c) decrease
describe the changes in arterial PO2, arterial PCO2, and arterial pH that occur in a healthy athlete during strenuous exercise
all remain the same
during exercise, what happens to lung-diffusing capacity and why?
increases because blood flow is continuous in all pulmonary capillaries during exercise
when cardiac output increases to a maximum, what happens to the pulmonary vasculature?
- pulmonary blood flow increases
- vessels enlarge (distension)
- recruitment & distension of pulmonary vessels lowers pulmonary vasculature resistance and maintains low pulmonary BP
