IV Capillary Exchange

Question 1

What causes hydrostatic pressure in the capillaries?

Answer 1

pressure of fluid on the capillary walls either by the blood plasma or interstitial fluid.

Question 2

What causes osmotic pressure in the capillaries?

Answer 2

(Solutes) proteins either in the blood plasma or interstitial fluid.

Question 3

Outward pressures at ARTERIOLAR END

Answer 3

Blood Hydrostatic - 30 mmHg
Interstitial Osmotic 8 mmHg
Interstitial Hydrostatic 3 mmHg

Total = 41 mmHg

Question 4

Inward pressures at ARTERIOLAR END

Answer 4

Blood capillary Osmotic pressure 28 mmHg

Question 5

Net Filtration pressure and impact

Answer 5

41 mmHg - 28 mmHg = 13 mmHg

Forces plasma OUT of capillaries with O2 and Nutrients

Question 6

Main source of OUTWARD pressure at ARTERIOLAR END?

Answer 6

Blood hydrostatic pressure

Question 7

Outwards pressures at VENULE END

Answer 7

Blood hydrostatic (drops) 10 mmHg
Interstitial Osmotic 8 mmHg
Interstitial hydrostatic 3 mmHg

Total OUT = 21 mmHg

Question 8

Inward pressures at VENULE END

Answer 8

Blood capillary Osmotic pressure at 28 mmHg (does not change!)

Question 9

Net amount returned

Answer 9

~7 mmHg

Question 10

What doesn’t return when reabsorbed at VENULE end?

Answer 10

small amount of leaked plasma