PATHOLOGY

Detailed explanation-1: -Blood flow is slowest in the capillaries, which allows time for exchange of gases and nutrients. Resistance is a force that opposes the flow of a fluid. In blood vessels, most of the resistance is due to vessel diameter.

Detailed explanation-2: -The velocity of blood flow is inversely proportional to the cross-sectional area of the blood vessel. The total cross-sectional area of capillaries is greater than the total cross-sectional area of the arteries and veins . Hence blood flow is lowest in the capillaries.

Detailed explanation-3: -Answer and Explanation: The blood velocity is higher in large veins than in the capillaries. The cross-sectional area of capillaries is the largest, the larger this area is, the slower the velocity of blood is. And so blood in large veins travels faster than in capillaries.