There are several factors which affect normal vision and eyesight. These factors include diet, heredity, environmental factors including exposure to artificial light, age, etc. Hormones can also affect our vision considerably.
The flow of blood in the capillaries is controlled by structures called precapillary sphincters. These structures are located between arterioles and capillaries and contain muscle fibers that allow them to contract. When the sphincters are open, blood flows freely to the capillary beds of body tissue.When the sphincters are closed, blood is not allowed to flow through the capillary beds. Fluid exchange between the capillaries and the body tissues takes place at the capillary bed.hen the sphincters are open, blood flows freely to the capillary beds of body tissue. When the sphincters are closed, blood is not allowed to flow through the capillary beds. Fluid exchange between the capillaries and the body tissues takes place at the capillary bed.
Split and merge into it. Answer by April Dixon. A band of smooth muscle that regulates blood flow through the capillaries are called precapillary sphincters. The total Cross-sectional area of all the Capillaries in the body is much greater than that of any other set of blood vessels. This gives it a very low Pressure, compair â¦ ed to things like the Arteries and the Aorta, meaning the blood is not being forced out of them as much.