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.
Arterioles carry the blood to the capillaries, which are not innervated, have no smooth muscle, and are about 5-8 Âµm in diameter. Blood flows out of the capillaries into the venules, which have little smooth muscle and are 10-200 Âµm. The blood flows from the venules into the veins.In addition to these blood vessels, the microcirculation also includes lymphatic capillaries and collecting ducts.rterioles carry the blood to the capillaries, which are not innervated, have no smooth muscle, and are about 5-8 Âµm in diameter. Blood flows out of the capillaries into the venules, which have little smooth muscle and are 10-200 Âµm. The blood flows from the venules into the veins.