GMS6402 MAIN EXAM SETS 2025/2026 QUESTIONS
AND SOLUTIONS GRADED A+ TIP
✔✔all diffusion will be complete in how long even though a RBC is in the capillary bed
for 0.75 seconds and crosses 3 alveoli - ✔✔0.25 seconds
✔✔what % of CO does the pulmonary circulation receive - ✔✔100%
✔✔pulmonary circulation is... - ✔✔high flow
low pressure
high compliance
✔✔how many mls of blood are in the lungs at rest and during exercise - ✔✔75 mls at
rest
100 mls during exercise
✔✔what happens first in the pulmonary capillaries, recruitment or distension -
✔✔recruitment
✔✔are the lungs uniformly ventilated - ✔✔no, more ventilation at base of lung than at
apex
✔✔why is there less blood perfusion at apex of lungs - ✔✔low pressure, can't get blood
all the way up there
✔✔how does the V/Q ratio change from base to apex - ✔✔increases
✔✔where would you find tuberculosis bacteria in a lung, base or apex - ✔✔apex, has
higher PAO2
✔✔shunt - ✔✔V/Q = 0
lungs not ventilated
are perfused with blood
alveolar gas resembles venous blood
✔✔what is the normal V/Q ratio - ✔✔0.8 (4.2/5.5)
✔✔pulmonary embolism V/Q - ✔✔V/Q = infinity
lungs are ventilated
no perfusion
, alveolar gas resembles inspired air
✔✔what are the 5 causes of clinical hypoxemia and what is the most common - ✔✔-
hypoventilation
-altitude
-diffusion limitation
-shunt
-V/Q mis-match (most common)
✔✔how can we see V/Q mismatch in a clinic - ✔✔-inhaled 133Xe
-chest x-ray
-radio-labeled serum, albumin lung scan
✔✔low flow disorder - ✔✔pulmonary embolism
blood clot forms and then detaches, returns to heart and then to lungs, gets stuck in
large pulmonary vessel, lowers blood flow to lungs
✔✔left heart failure - ✔✔high pressure disorder
cannot maintain CO, blood backs up in left heart and into lungs, causes hydrostatic
pressure to rise, high pressure forces water out of blood and into alveoli, alveoli now
useless
✔✔pulmonary hypertension - ✔✔high pressure disorder
due to endothelial cell dysfunction in lung, increased hydrostatic pressure, pulmonary
edema
✔✔postprandial dyspnea - ✔✔high pressure disorder
increase blood volume, higher pulmonary pressure, water into alveoli, cannot increase
volume of pleural space
✔✔pulmonary edema - ✔✔increases path of diffusion, washes away surfactant
increase work of breathing
alveoli collapse, lose ventilation
most commonly due to increased hydrostatic pressure that pushes fluid out of the
capillaries
shunting
AND SOLUTIONS GRADED A+ TIP
✔✔all diffusion will be complete in how long even though a RBC is in the capillary bed
for 0.75 seconds and crosses 3 alveoli - ✔✔0.25 seconds
✔✔what % of CO does the pulmonary circulation receive - ✔✔100%
✔✔pulmonary circulation is... - ✔✔high flow
low pressure
high compliance
✔✔how many mls of blood are in the lungs at rest and during exercise - ✔✔75 mls at
rest
100 mls during exercise
✔✔what happens first in the pulmonary capillaries, recruitment or distension -
✔✔recruitment
✔✔are the lungs uniformly ventilated - ✔✔no, more ventilation at base of lung than at
apex
✔✔why is there less blood perfusion at apex of lungs - ✔✔low pressure, can't get blood
all the way up there
✔✔how does the V/Q ratio change from base to apex - ✔✔increases
✔✔where would you find tuberculosis bacteria in a lung, base or apex - ✔✔apex, has
higher PAO2
✔✔shunt - ✔✔V/Q = 0
lungs not ventilated
are perfused with blood
alveolar gas resembles venous blood
✔✔what is the normal V/Q ratio - ✔✔0.8 (4.2/5.5)
✔✔pulmonary embolism V/Q - ✔✔V/Q = infinity
lungs are ventilated
no perfusion
, alveolar gas resembles inspired air
✔✔what are the 5 causes of clinical hypoxemia and what is the most common - ✔✔-
hypoventilation
-altitude
-diffusion limitation
-shunt
-V/Q mis-match (most common)
✔✔how can we see V/Q mismatch in a clinic - ✔✔-inhaled 133Xe
-chest x-ray
-radio-labeled serum, albumin lung scan
✔✔low flow disorder - ✔✔pulmonary embolism
blood clot forms and then detaches, returns to heart and then to lungs, gets stuck in
large pulmonary vessel, lowers blood flow to lungs
✔✔left heart failure - ✔✔high pressure disorder
cannot maintain CO, blood backs up in left heart and into lungs, causes hydrostatic
pressure to rise, high pressure forces water out of blood and into alveoli, alveoli now
useless
✔✔pulmonary hypertension - ✔✔high pressure disorder
due to endothelial cell dysfunction in lung, increased hydrostatic pressure, pulmonary
edema
✔✔postprandial dyspnea - ✔✔high pressure disorder
increase blood volume, higher pulmonary pressure, water into alveoli, cannot increase
volume of pleural space
✔✔pulmonary edema - ✔✔increases path of diffusion, washes away surfactant
increase work of breathing
alveoli collapse, lose ventilation
most commonly due to increased hydrostatic pressure that pushes fluid out of the
capillaries
shunting
