KIDNEY

Kidney
The kidneys are two bean-shaped organs about the size of a fist. They were near the midline of the back, just below the box that forms the ribs. In each kidney there are about a million tiny structures called nephrons, which filter the blood. Kidney, removing waste products and excess water, which turns into the urine. Urine flows through tubes called ureters to the bladder, where urine is stored and then released during urination.
Most kidney diseases attack the nephrons. This damage causes the kidneys can not eliminate waste. Causes include genetic problems, drug contraindications.