It is this cycle that causes what we think of as every day hair loss -- most people lose between 50 to 100 hairs each day. And on days when we shampoo, we tend to lose more, says Amy McMichael, M.D., a professor of dermatology at Wake Forest Baptist Health.
1 Cells where infection or other damage is occurring release substances like histamine that dilate the arterioles and thus increase blood flow in the area. [ 2  Link to discussion of inflammation. ]. 3  In most of the body, the flow of blood through a capillary is controlled by the arteriole supplying it.ontrol of the Capillary Beds. An adult human has been estimated to have some 60,000 miles (96,560 km) of capillaries with a total surface area of some 800â1000 m 2 (an area greater than three tennis courts). The total volume of this system is roughly 5 liters, the same as the total volume of blood.
Blood Flow. Blood flow refers to the movement of blood through the vessels from arteries to the capillaries and then into the veins. Pressure is a measure of the force that the blood exerts against the vessel walls as it moves the blood through the vessels.Like all fluids, blood flows from a high pressure area to a region with lower pressure. Blood flows in the same direction as the decreasing pressure gradient: arteries to capillaries to veins.The rate, or velocity, of blood flow varies inversely with the total cross-sectional area of the blood 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. Resistance is a force that opposes the flow of a fluid.ressure is a measure of the force that the blood exerts against the vessel walls as it moves the blood through the vessels. Like all fluids, blood flows from a high pressure area to a region with lower pressure. Blood flows in the same direction as the decreasing pressure gradient: arteries to capillaries to veins.