Red blood cells move completely throughout the body in approximately 20 seconds. Technically known as erythrocytes, red blood cells’ primary function is to deliver oxygen from the lungs to body tissues by circulating blood. Approximately 45% of the blood is comprised of red blood cells, and the body’s bone marrow produces around 2.4 million new red blood cells every second. In times of stress, the body is capable of producing over 100 million new red blood cells per second. Red blood cells flow through the body for approximately 120 days before being broken down and removed by white blood cells. One ounce of blood will typically contain around 150 billion red blood cells.
More about blood: