Renal Cortex

The renal cortex is the outer region of the functional tissue, or parenchyma, of the kidney, lying beneath the renal capsule and surrounding the inner renal medulla. It contains most of the structures involved in the initial filtration and processing of blood by the nephrons, the functional units of the kidney .¹

All renal corpuscles are located in the cortex. Each renal corpuscle consists of a glomerulus, a tuft of capillaries where fluid is filtered from the blood, enclosed by Bowman’s capsule. The cortex also contains the proximal and distal convoluted tubules, along with cortical portions of collecting tubules and collecting ducts. Cortical tissue extends between the renal pyramids as structures called renal columns .¹

The renal cortex receives a large blood supply. Blood reaches the glomeruli through afferent arterioles, and efferent arterioles leaving the glomeruli contribute to capillary networks that surround the renal tubules. This circulation supports both glomerular filtration and the subsequent reabsorption and secretion of substances between tubular fluid and blood .^1,2

The renal cortex is distinct from the renal medulla. The cortex contains the glomeruli and convoluted portions of the nephrons, whereas the medulla is organized into renal pyramids containing portions of the loops of Henle and collecting ducts. Differences in their blood flow and tissue environment contribute to kidney function, particularly the medulla’s role in concentrating urine .^1,2