Question

Which statement describes the net movement of water at the arterial end of a Capillary bed?

A) Water moves into the capillary
B) Water moves out of the capillary
C) No net movement of water
D) Water moves in and out equally

Answer 1

Water moves out of the capillary at the arterial end due to filtration, as a result of the higher capillary hydrostatic pressure compared to blood colloidal osmotic pressure. The correct option is B).

Step-by-step explanation:

The net movement of water at the arterial end of a capillary bed is that water moves out of the capillary.

This process is known as filtration and occurs because the capillary hydrostatic pressure (CHP) is higher than the blood colloidal osmotic pressure (BCOP) at the arterial end, creating a net filtration pressure (NFP) that drives the movement of water out of the capillaries and into the surrounding tissues.

Specifically, the CHP at the arterial end is approximately 35 mm Hg, while the BCOP is about 25 mm Hg, resulting in an NFP of 10 mm Hg, which causes the net movement of fluid out of the capillary. Option B) is the correct one.