Anaemia: affects the function of the circulatory system
Increased cardiac output in people with partial anaemia compensates for the lack of oxygen due to anaemia because although each number of blood units carries only a small amount of oxygen, the blood flow can increase enough to an almost normal amount of oxygen. oxygen to the tissues.
The viscosity of the blood largely depends on the concentration of red blood cells. In people with severe anaemia, the blood viscosity can drop as low as 1.5 times that of water. The normal value is about 3. This change reduces the friction of the flow of blood in the peripheral blood vessels, so a larger amount of blood flow through the tissue and back to the heart, thus making significantly increases the amount of blood the heart pumps out. Furthermore, transport-induced hypoxia causes tissue peripheral blood vessels to dilate, increasing blood return to the heart, and increasing cardiac output three to four times higher than normal sometimes. Thus, one of the main effects of anaemia is a multiplicative increase in cardiac output, as well as an increase in the heart's pumping flow.
The increase in cardiac output in people with partial anaemia compensates for the lack of oxygen due to anaemia because although each number of blood units carries only a small amount of oxygen, the blood flow can be increased by an almost normal amount. of oxygen to the tissues.
However, when a person with anaemia begins to exercise, the heart is unable to pump much larger amounts. Consequently, during exercise, the tissue oxygen demand increases significantly, causing severe tissue hypoxia and acute heart failure.