Why does blood pressure decrease as the blood travels from

arteriesto arterioles to capillaries?

Blood flows in the same direction as the decreasing gradient of pressure: arteries into veins into capillaries. The blood flow rate, or velocity, varies inversely with the blood vessel's total cross-sectional area. As the vessel's overall cross-sectional area increases, the flow rate decreases. Blood flow in the capillaries is slowest, allowing time for gas and nutrient exchange. Resistance is a force resisting a fluid's flow. Most of the resistance in blood vessels is due to the diameter of the vessel. The resistance increases as the diameter of the vessel decreases and the blood flow decreases. The moment the blood exits the capillaries and reaches the venules stays very low pressure. The direct result of ventricular contraction is not the blood flow through the veins. Alternatively, venous return relies on the function of the skeletal muscle, breathing movements, and smooth muscle constriction in venous walls.