Problem 6

Background and context

The kidneys have three regions: renal cortex, renal medulla, and renal pelvis. At the microscopic level, the cortex and medulla contain the nephrons. A nephron has a glomerular capsule, proximal convoluted tubule, nephron loop, distal convoluted tubule, and collecting duct. Urine formation requires three steps: filtration, reabsorption, and secretion. Production of hypertonic urine occurs when water is reabsorbed into the blood along the length of the nephron, and especially at the nephron loop and collecting duct.