How do the renal cortex and renal medulla differ?

The renal cortex and renal medulla are the two primary structural sections of the mammalian kidney, distinguished by their location, composition, and specific roles in urine production.1

• Renal Cortex: This is the granular outer layer of the kidney. It contains the renal corpuscles (glomeruli and Bowman’s capsules) and the convoluted tubules of the nephrons. The cortex is the site where initial urine filtration occurs, and it receives the majority of the kidney's blood supply.123
• Renal Medulla: This is the smooth, striated inner section of the kidney. It is composed of triangular tissue segments called renal pyramids, which contain the loops of Henle and collecting tubules. The medulla plays a critical role in concentrating urine by maintaining a high concentration of solutes in the surrounding interstitial fluid, a process that relies on the specific transport characteristics of the loops of Henle.1425

While these regions are distinct, they function as an integrated system to filter blood, reabsorb essential nutrients, and regulate water balance.1