Nephron Over a million in each kidney Functional unit of the kidney Each has its own blood supply provided by 2 capillary regions Two capillary beds: Glomerulus Peritubular Role is to filter wastes while retaining water and other vital materials. Located almost entirely in the cortex
Bowman’s Capsule Closed end of a nephron Location where wastes are forced out of the blood and into the nephron Outer layer made up of squamous epithelial cells Found in the renal cortex Surrounds the glomerulus
Glomerulus Knot of capillaries inside the Bowman’s capsule Found in the renal cortex
Afferent Arteriole Carries blood to the glomerulus
Efferent Arteriole Carries blood away from the glomerulus Connects to the peritubular capillaries
Renal Tubule Consists of Bowman’s capsule Rest of the tubule divided into 3 regions
Rest of tubule About 1.25 inch long Coils and twists before entering the collecting duct 3 regions of tubule: Proximal convoluted Loop of Henle Distal convoluted
Proximal Convoluted Tubule Narrow region of the nephron after the Bowman’s capsule Each cell has many mitochondria that supply energy for active transport of molecules from the lumen to the peritubular capillary network Found in the renal cortex
Loop of Henle U-turn making loop in the tubule Consists of a descending limb that allows water to leave and an ascending limb where NaCl leaves Found in the renal medulla
Distal convoluted tubule Last region of renal tubule Each cell has many mitochondria, once again involved in active transport Found in the renal cortex
Collecting Duct Distal convoluted tubules of several nephrons enter one collecting duct Many collecting ducts in each kidney Carries urine to the renal pelvis Found in the renal medulla
Capillary Beds Glomerulus Specialized for filtration Unlike any other in the body because it is both fed and drained by arterioles, which are high-resistance vessels
Capillary Beds Peritubular Capillary Bed Surrounds the renal tubule Involved in reabsorption of nutrients and water Low-pressure, porous vessels