Diapedesis, also known as extravasation, is the process by which blood cells, particularly white blood cells or leukocytes, pass through the walls of blood vessels and into the surrounding tissue. This is a normal physiological process that occurs during inflammation or in response to infection or injury, as white blood cells migrate from the bloodstream to the site of tissue damage to combat invading pathogens or damaged cells. During diapedesis, the white blood cells change their shape to squeeze through the gaps between the cells that make up the walls of the blood vessels, and then move along a chemical gradient towards the site of injury or infection. Once they have reached the site, they can carry out their immune functions, such as phagocytosis or the release of antimicrobial compounds.
