Answer:
a. True
Explanation:
Arteries, capillaries, arterioles and precapillary sphincters are of utmost importance in the circulatory system.
The arteries before they become capillaries are somewhat smaller and are called arterioles, and the capillary when it becomes a vein again has an intermediate passage in what are smaller veins called venules; Precapillary sphincters branch the main channels, open or close other parts of the capital bed to meet the varying needs of the tissue. In this way, the sphincters and smooth muscle of veins and arteries regulate the supply of blood to the organs.
Thus, we can conclude that precapillary sphincters increase blood flow through a tissue when they relax.
