sciencephotolibrary:

Phagocytosis. Coloured scanning electron micrograph (SEM) of a macrophage white blood cell (green) phagocytosing (engulfing) bacteria (yellow). The macrophage, part of the body’s immune system, surrounds the bacteria, engulfs them and destroys them, a process known as phagocytosis.

Credit: BIOPHOTO ASSOCIATES/SCIENCE PHOTO LIBRARY