Control of blood water potential

• Collecting duct = tube into which a number of distal convoluted tubules from a number of nephrons empty. It is lined by epithelial cells and becomes increasingly wide as it empties into the pelvis of the kidney
• Loop of Henle = long loop that extends from the cortex into the medulla of the kidney and back again, surrounded by blood capillaries
• Efferent arteriole = tiny vessel that leaves the capsule and has a smaller diameter than the afferent arteriole, causing an increase in blood pressure within the glomerulus
• Afferent arteriole = tiny vessel that arises from the renal artery and supplies the nephron with blood
• Renal capsule = closed end at the start of the nephron which is cup-shaped and surrounds a mass of blood capillaries called the glomerulus. The inner layer is made of specialised cells called podocytes
• Distal convoluted tubule = series of loops surrounded by blood capillaries. Its walls are made of epithelial cells
• Glomerulus = knot of capillaries from which the fluid is forced out of the blood
• Proximal convoluted tubule = series of loops surrounded by blood capillaries. Its walls are made of epithelial cells which have microvilli