Light micrograph of a section through the cortex of a kidney. The cortex of the kidney consists mainly of blood vessels and filtering units (one at left). The filtering units are made up of a glomerulus (purple) and a Bowman's capsule (white). The core of each glomerulus is formed of a tightly coiled capillary. Its function is to filter waste products from the blood. After the reabsorption of minerals and water in the tubules (pink, surrounding the glomeruli), the liquid is transported to the bladder as urine. Magnification: x400 when printed at 15cm wide.