Why is it important that the blood flow is the slowest of al

Why is it important that the blood flow is the slowest of all vessels in the capillaries?

Solution

Answer:

The velocity of blood flow varies inversely with the total cross-sectional area of the vessels. As the total cross-sectional area of the vessels increases, the velocity of flow decreases. Blood flow is slowest in the capillaries, which allows time for exchange of gases and nutrients.