All of the following are present in arterioles and in capillaries except
A)fully oxygenated blood.
B)plasma in which carbon dioxide has been added.
C)a lining of endothelial cells.
D)circular smooth muscle cells.
E)white blood cells and platelets.

Question

Quizplus · Accepted Answer

Arterioles contain circular smooth muscle cells in their walls which allow for the regulation of blood flow and pressure. Capillaries, however, lack these smooth muscle cells; they are primarily composed of a thin layer of endothelial cells to facilitate the exchange of gases, nutrients, and waste products between blood and tissues.

All of the Following Are Present in Arterioles and in Capillaries