Removal of red blood cells in the liver: false- colour scanning electron micrograph (SEM) showing the phagocytosis of red blood cells (red discs) by a Kupffer cell, a type of tissue-fixed macrophage in the sinusoids of the liver. The lining of the porous capillaries or sinusoids of the liver is composed of 2 cell types: endothelial cells (bronze) and Kupffer cells (yellow), which are highly irregular in shape. The Kupffer cells serve to purge blood of old, redundant red blood cells by engulfing & breaking them down in a process called phagocytosis. Magnification: 31970 at 637cm size. Cover credit: PROF. P. MOTTA/DEPT. OF ANATOMY/UNIVERSITY “LA SAPIENZA”, ROME/SCIENCE PHOTO LIBRARY.