The renal or kidney medulla is the inner part of the kidney. The medulla helps regulate the concentration of urine by filtering out water, salts, and acid. The National Institute of Diabetes and ...

Renal papillae are the structures that are at the tips of the pyramids, and they point towards the renal pelvis. On average, there are approximately 8 renal pyramids in each kidney.

The renal corpuscles, as well as the proximal and distal convoluted tubules are found here. It reaches into the inner renal tissue or medulla, splitting it into triangular parts called renal pyramids.

Location refers to the presence of tumor nodules between renal pyramids or bracketed by renal medulla and cortex, the normal location of intralobar and arcuate veins (Figures 4b, 6 and 7).