Question

Given the following forces acting at a given point across the capillary wall, what type of fluid movement will be taking place at that point?

– capillary blood pressure = 32 mm Hg
– blood-colloid osmotic pressure = 23 mm Hg
– interstitial-fluid hydrostatic pressure = 1 mm Hg
– interstitial-fluid-colloid osmotic pressure = 0 mm Hg
a. Ultrafiltration will occur with a net outward pressure of 8 mm Hg.
b. Ultrafiltration will occur with a net outward pressure of 10 mm Hg.
c. Ultrafiltration will occur with a net outward pressure of 56 mm Hg.
d. Reabsorption will occur with a net inward pressure of 24 mm Hg.

Answer 1

Answer: The movement of fluid across the capillary wall is determined by the balance between the four forces: capillary blood pressure, blood-colloid osmotic pressure, interstitial-fluid hydrostatic pressure, and interstitial-fluid-colloid osmotic pressure.

The net filtration pressure is calculated as the difference between the forces promoting filtration (capillary blood pressure and interstitial-fluid-colloid osmotic pressure) and the forces opposing filtration (blood-colloid osmotic pressure and interstitial-fluid hydrostatic pressure).

Net filtration pressure = (capillary blood pressure + interstitial-fluid-colloid osmotic pressure) - (blood-colloid osmotic pressure + interstitial-fluid hydrostatic pressure)

Substituting the given values into the equation, we get:

Net filtration pressure = (32 mm Hg + 0 mm Hg) - (23 mm Hg + 1 mm Hg) = 8 mm Hg

Since the net filtration pressure is positive and the pressure is outward, ultrafiltration will occur. Therefore, the correct answer is option a: Ultrafiltration will occur with a net outward pressure of 8 mm Hg.

Step-by-step explanation: