The Material Present in Arterioles That is Not Present in Capillaries

Question

The material present in arterioles that is not present in capillaries is
A)fully oxygenated blood.
B)plasma in which carbon dioxide has been added.
C)a lining of endothelial cells.
D)circular smooth muscle cells that can alter the size of the arterioles.
E)white blood cells and platelets.

Accepted Answer

Arterioles have a lining of endothelial cells and plasma, just like capillaries. However, arterioles have circular smooth muscle cells that can alter their size, allowing them to control blood flow and pressure. Fully oxygenated blood can be present in both arterioles and capillaries, so A is not correct. Plasma in which carbon dioxide has been added is present in veins, not arterioles or capillaries, so B is not correct. White blood cells and platelets can be present in both arterioles and capillaries, so E is not correct.