There are three parts of the kidney and they are included in the genitourinary system. Within the renal pelvis are other structures. Urine formed in the kidney passes through renal papilla at the apex (the tip of a pyramidal structure) into a minor calyx (a flower-shaped structure, especially one in the pelvis of the kidney) then into a major calyx before passing into the renal pelvis and into the ureter.

The renal pelvis is shaped like a funnel. It is the point of convergence of two or three major calyces. Each renal papilla is surrounded by a branch of the renal pelvis called a called a calyx. The smooth muscle in the calyx uses the action of peristalsis to move the urine into the renal pelvis. The renal pelvis is covered with transitional epithelium, and an underlying lamina propria of loose and dense connective tissue.

The ureter is the tube that forms the spout of this funnel-shaped renal pelvis. The 10-12 inches long ureter is where the urine is lead on its’ way to the urinary bladder. Another name for the renal bladder is pyelum. The major function of the renal pelvis is to act as a funnel for urine flowing to the ureter.