Structure: The Kidney

The kidney has three regions: the cortex, the medulla, and the renal pelvis. The outer layer, the cortex, contains filtering units called nephrons, each consisting of a glomerulus and a renal tubule. The middle layer, the medulla, consists of cone-shaped groups of urine-collecting ducts. The inner region, the renal pelvis, branches into cavities called major and minor calyces. Each minor calyx gathers urine from the medulla; the urine is then collected in major calyces and funnelled into the ureter.

Filtering unit

This knot of capillaries, called a glomerulus, is where blood is filtered; filtrate enters the glomerular capsule.


These structures, which are the kidney’s filtering units, consist of a glomerulus and a renal tubule.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

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