What is the most superficial region of the kidney?

While the cortex is the superficial outer layer of the kidney located underneath the capsule; the renal cortex is the most superficial part of the kidney. It is the outer region of the kidney between the renal capsule and the renal medulla where ultrafiltration occurs. Looking at the kidney, you'll observe that the renal cortex is a layer of tissue that contains tiny blood vessels, blood filters called nephrons, and collecting ducts that lead to the center region of the kidney. It contains a major portion or the nephrons and all cortical radiate arteries.