Hematocrit is defined as the percentage of blood made up of what component?

Hematocrit is defined as the percentage of blood volume that is composed of red blood cells. This measurement is crucial in hematology as it helps in assessing the oxygen-carrying capacity of blood and evaluating various health conditions such as anemia, polycythemia, and other disorders.

Red blood cells, or erythrocytes, are the primary component of hematocrit because they play a major role in the transport of oxygen from the lungs to the tissues and the return of carbon dioxide from the tissues to the lungs. A higher or lower hematocrit value can indicate various physiological or pathological conditions affecting the production, destruction, or loss of these cells.

Serum is the liquid portion of blood that remains after the clotting factors have been removed, and it does not contribute to hematocrit levels. White blood cells are essential for the immune response but constitute only a small percentage of blood volume compared to red blood cells, and platelets, which aid in clotting, also represent a minor proportion. Thus, they are not considered in the definition of hematocrit.