SCIENCE PICTURES LTD / SCIENCE PHOTO LIBRARY SCIENCE PICTURES LTD / SCIENCE PHOTO LIBRARY
Red blood cells. Light micrograph of a human blood smear showing red blood cells (erythrocytes). Red blood cells are the most abundant type of blood cell in human blood. Every cubic millimetre of blood contains around 5 million of these tiny, flexible, biconcave disc-like cells. The cells have no nucleus. The red colour comes from the pigment haemoglobin which picks up oxygen in the lungs and distributes it around the body. As red blood cells are subjected to constant physical pounding in the blood vessels, they have a short lifespan. After about four months they are broken down and replaced. Magnification: x400 at 35mm size.
Model release not required. Property release not required.