Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries?

Answer 1

By the time the blood gets to the capillary bed, the blood pressure has dropped very low. This is important since this allows time for oxygen and nutrients to be dropped off and wastes and carbon dioxide to be picked up. By the way, the capillaries are so small that the red blood cells can barely fit through. They have to bend to fit. That also slows things down.

Answer 2

Yes, this gives more time for diffusion of substances (like oxygen and carbon dioxide) between the blood and cells.

Answer 3

Blood flows slowest in the capillaries since the capillaries have the largest cross-sectional area. Blood flow is inversely related to cross-sectional area.

Answer 4

Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.

Answer 5

The slow flow of blood in the capillaries maximizes opportunities for diffusion. This diffusion is what moves nutrients, oxygen, and wastes into and out of the bloodstream.

Answer 6

Slow blood flow in capillaries increases the opportunity for diffusion of nutrients, oxygen, and wastes. The thin capillary wall also assists with this function.

Answer 7

The slow blood flow through the capillaries increases the efficiency of diffusion. This speed helps get oxygen, nutrients, and wastes to and from the body tissues.

Answer 8

To allow time for gas exchange to occur.

Answer 9

because capillaries have a small lumen