Sat27November0445PM 10

Starling forces can be applied to the pulmonary microcirculation in the same way as any other capillary bed.

Which one of the following pressures best approximates to interstitial oncotic pressure acting across a normal pulmonary capillary?

(Please select 1 option)

17 mmHg Correct

25 mmHg

0 mmHg

6 mmHg

13 mmHg

Explanation

The typical values of the Starling forces acting across normal pulmonary capillaries are as follows:

Interstitial oncotic pressure = 17 mmHg (estimated from measurements on pulmonary lymph)

Capillary hydrostatic pressure (Pc) is 13 mmHg (arteriolar end) to 6 mmHg (venous end) but variable because of the hydrostatic effects of gravity especially in the erect lung.

Interstitial hydrostatic pressure (Pi) - Variable but ranges from zero to slightly negative.

Capillary oncotic pressure = 25 mmHg.

Answer Statistics

1

15%

2

14%

3

12%

4

37%

5

25%

Times answered: 241