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.
At the origin of each capillary from an arteriole, there is a ring of smooth muscle called the precapillary sphincter that controls the flow of blood entering it. Sympathetic nerves innervate it. In this way, the nervous system can control blood flow through individual capillaries.he volume (mL) of blood that flows through any tissue in a given period of time (min) is blood flow (ml./min). The velocity of blood flow (in cm/sec) is inversely related to the cross-sectional area of the blood vessels. In other words, blood flows slowest where the total cross sectional area is greatest.