Erythrocyte definition
What is Erythrocyte and Definition
A red BLOOD cell (RBC). The primary function of erythrocytes is to carry oxygen from the LUNGS to the cells of tissues throughout the body and return carbon dioxide, a metabolic waste, to the lungs for removal from the body. Erythrocytes contain iron and HEMOGLOBIN, a pigmented protein that gives them their red color. Hemoglobin is the substance to which oxygen and carbon dioxide molecules bind for transport through the bloodstream. Erythrocytes account for 99 percent of the blood cells the blood carries.
Erythrocyte Count
Erythrocytes lack nuclei, which means they cannot proliferate (reproduce). They have a lifespan of about 120 days. The BONE MARROW thus must continuously produce erythrocytes, which it does at the rate of about 2 million per minute. The SPLEEN and the LIVER filter aging, deteriorating, and defective erythrocytes from the blood circulation. Men have a somewhat higher percentage of erythrocytes in their blood, about 47 percent, than women, who have about 42 percent, primarily because women lose blood each month with MENSTRUATION. The number of erythrocytes in both men and women begins to decline after age 70 because erythropoiesis slows as a natural aspect of aging.
For further discussion of erythrocytes within the context of blood and lymph structure and function please see the overview section “The Blood and Lymph.”
See also HEMATOPOIESIS; OXYGEN-CARBON DIOXIDE EXCHANGE.
