Blood cells. Coloured scanning electron micrograph (SEM) of
red blood cells (erythrocytes, red), white blood cells
(leukocytes, white), and platelets (thrombocytes, green).
The disc-shaped, biconcave erythrocytes transport oxygen to
the body's cells and remove carbon dioxide to the lungs.
Leukocytes are part of the immune system, defending the body
against infection by ingesting pathogens by phagocytosis or
by producing antibodies. Thrombocytes are involved with
blood clotting. They gather at sites of injury and produce
clotting factor. Magnification: x5600 when printed 10