Nephrons are units of the kidney which are specially adapted for filtration and reabsorption of substances in the blood. Each nephron is composed of different various parts which have specific roles. These parts are called; the glomerulus, Bowman's capsule, the proximal convoluted tubule, the loop of Henle, the distal convoluted tubule and the collecting duct. The substances left over in the collecting duct form urine and are transported via the ureter to the bladder.