The Kidney

The Kidneys You have two of them – the size of your fist! Located in the middle of your back, right at the 12th rib.

Function to…. Regulate the composition of your blood Keep the concentrations of various ions and other important substances constant Keep the volume of water in your body constant Remove wastes from your body (urea, ammonia, drugs, toxic substances) Keep the acid/base concentration of your blood constant Help regulate your blood pressure Stimulate the making of red blood cells (Erythropoietin) Maintain your body's calcium levels Metabolizes Vitamin D to the active form your body can use.

Blood Flow Your kidneys receive the blood from the renal artery process it return the processed blood to the body through the renal vein and­ remove the wastes and other unwanted substances in the urine. Label the renal artery, renal vein

Structures of the Kidney Renal Capsule tough fibrous layer surrounding the kidney Renal Cortex The outer part of the kidney Contains the renal corpuscles and renal tubules

Structures of the Kidney Medulla – Innermost part of the kidney Split into the Renal Pyramids (Medullary Pyramids contains the structures of the nephrons responsible for maintaining the salt and water balance of the blood. Loop of Henle Collecting Tubule Space between the pyramids is known as the renal column

Structures of the Kidney Calyx- Moves urine from collecting duct to renal pelvis Renal Pelvis- The point of convergence of the calyces. Urine funnels into the ureter from this point.

Nephron Functional unit of the kidney Found in cortex and medulla Regulates water concentration Filters blood Reabsorbs necessary ions and substances Creates urine http://www.biologymad.com/resources/kidney.swf

Bowman’s Capsule The Bowman's capsule contains the primary filtering device of the nephron, the glomerulus. Blood is transported into the Bowman's capsule from the afferent arteriole. Filtered water and aqueous wastes are passed out of the Bowman's capsule into the proximal convoluted tubule.

Glomerulus The main filter of the nephron Located within the Bowman's capsule Made of a ball of capillaries Semipermeable allowing water and soluble wastes to pass through and be excreted out of the Bowman's capsule as urine. Filtered blood passes into the efferent areteriole to be returned to the body.