The renal papilla is a blunted apex that projects into the renal pelvis through which the collecting tubules discharge. It is the location where the Medullary pyramids empty urine into the renal pelvis. Histologically, the renal papilla is marked by medullary collecting ducts converging to channel the fluid. Transitional epithelium begins to be seen.
Damage to the renal papillae may result in death to cells in this region of the kidney, called renal papillary necrosis.