What term describes the volume percentage of red blood cells in whole blood per 100 mL?

The term that describes the volume percentage of red blood cells in whole blood per 100 mL is known as hematocrit. This measurement is crucial in evaluating an individual's blood health, particularly in relation to anemia or polycythemia. Hematocrit indicates how much of the total blood volume is comprised of red blood cells, which are essential for transporting oxygen throughout the body.

Erythrocytes refer to the red blood cells themselves rather than a measurement or volume percentage. Leukocytes are white blood cells, which play a role in the immune response but do not contribute to the hematocrit value. Hemoglobin is a protein found within red blood cells that carries oxygen; while closely related to red blood cell function, it is not a measure of the volume percentage of these cells in the blood. This distinction is essential for understanding blood composition and the physiological roles of its components.