The kidneys are responsible for purifying the blood.  They are one of the best examples of homeostatic organas, organs responsible for maintaining a balance of elements.  They work muck like sanitation workers filtering and disposing of wastes from the blood.

     The kidneys are protected by floating ribs located in the mid back.  They are small dark red, bean-shaped organs.  Due to the placement of the liver, the right kidney is a bit lower than the left.

     The kidney is enclosed by a transparent, fiberous, renal capsule.  A mass of fat, known as the adipose capsule encases each kidney, and provides some protection.  The kidney can be divided into three regoins, the renal cortex, the renal medulla, and the renal pelvis. The renal cortex is the light colored, outer region of the kidney.  The renal medulla is the darker, reddish-brown region.