Definition of Renal medula?

The renal medulla is the innermost part of the kidney, located between the renal cortex and the renal pelvis. It is made up of renal pyramids, which are cone-shaped structures that contain the loops of Henle and collecting ducts of the nephrons. The renal medulla is responsible for regulating the concentration of urine and reabsorbing water and electrolytes to maintain the body's fluid balance.