Erythrocytes are red blood cells that carry oxygen and carbon dioxide in the body. Learn about their structure, function, life cycle and blood group antigens with examples and diagrams. The most abundant formed elements in blood, erythrocytes are red, biconcave disks packed with an oxygen-carrying compound called hemoglobin. The hemoglobin molecule contains four globin proteins bound to a pigment molecule called heme, which contains an ion of iron. In the bloodstream, iron picks up oxygen in the lungs and drops it off in the tissues; the amino acids in hemoglobin then transport carbon dioxide from the tissues back to the lungs. Erythrocytes live only 120 days on average ... Erythrocytes The erythrocytes (red blood cells) are flexible, biconcave disks that transport oxygen to the body tissues (Figure 1-4). Mammalian erythrocytes are unusual in that they lack a nucleus. The average erythrocyte is 7 µm in diameter, and these cells arise from pluripotential stem cells in the bone marrow.
