How well do you know the kidney?

The Structure and Function of the Kidney

• The kidney has three regions: the cortex, medulla, and renal pelvis.
• Each kidney contains around a million nephrons, which start in the cortex, loop down into the medulla, and back up to the cortex.
• The contents of the nephrons drain into the renal pelvis and the urine collects there before it flows into the ureter to be carried to the bladder for storage.
• The nephron is made up of a kidney tubule which has several sections: Bowman's capsule, proximal convoluted tubule, Loop of Henlé, distal convoluted tubule, and collecting duct.
• In the kidney, blood is filtered before the key substances are reabsorbed back into the blood again.
• The process occurs in the following order: ultrafiltration, selective reabsorption of glucose, and reabsorption of water and salts.
• Ultrafiltration occurs when arterioles branch off the renal artery and lead to each nephron, where they form a knot of capillaries (the glomerulus) sitting inside the cup-shaped Bowman’s capsule.
• As the filtrate drips through the Loop of Henle, necessary salts are reabsorbed back into the blood by diffusion.
• Water is also reabsorbed from the collecting duct in different amounts depending on how much water the body needs at that time.
• Glucose is the first substance to be reabsorbed at the proximal (first) convoluted tubule, and this takes place by active transport.
• Osmoregulation is the process of maintaining water and salt concentrations (osmotic balance) across membranes within the body.
• Maintaining water levels in the body is vital to prevent harmful changes occurring to cells of the body as a result of osmosis, and the water content of the body comes from two sources: water produced as a result of aerobic respiration and water in the diet.

Test your knowledge on the fascinating structure and function of the kidney with our quiz! From the three regions of the kidney to the million nephrons within it, this quiz explores the complex process of filtration and reabsorption that occurs in the kidney. See how much you know about ultrafiltration, osmoregulation, and the role of glucose, water, and salts in maintaining the body's balance. Take the quiz now and discover how much you really know about this vital organ.