Schematic presentation of the kidney inside the human body and the kidney structure.
The kidneys are part of the urogenital system. Each kidney is encapsulated by a fibrous outer layer called the renal capsule and comprised of, a peripheral layer called the cortex, and an inner layer called the medulla. The medulla is arranged in multiple pyramidal structures that together with overlying cortex comprise a renal lobe. Urine drains from the tip of each pyramid (papilla) into minor and major calices that empty into the renal pelvis. The renal pelvis then transmits the urine to the bladder via the ureter.