Caption

Kidney. Coloured Computed Tomography (CT) scan of a section through a whole healthy human kidney. The kidney is a bean-shaped organ located in the abdomen, of which there are two in the body. Each consists of an outer cortex (blue) and an inner medulla with pyramid- shaped units (orange/yellow). Blood enters the kidney through the renal artery (far left) and is passed into a network of capillaries in the cortex. These capillaries end in tiny glomeruli (not seen) which filter excess water and metabolic wastes from the blood into tubules, where the waste turns to urine. The urine drains through the medullary pyramids into the ureter (red) which leads to the bladder.