Coloured scanning electron micrograph (SEM) of a resin cast of glomeruli (orange) and capillaries in the renal corpuscle. Glomeruli are found in the kidneys. The core of a glomerulus is a tightly coiled ball of capillaries. The permeable capillary walls allow substances carried in the blood to be exchanged with the surrounding tissues. Each kidney has hundreds of glomeruli that filter waste from the blood. The resulting waste fluid drains to the bladder as urine. Magnification: x500 when printed at 15cm wide.