Which term corresponds to the major organ of the urinary system?

• A. Bladder
• B. Ureter
• C. Kidney
• D. Urethra

Answer: (C)

The kidneys are the major organ of the urinary system. They filter the blood to remove waste, produce urine, and regulate fluid volume, electrolyte balance, and acid-base status. They also release hormones such as erythropoietin, which helps regulate red blood cell production, and renin, which helps control blood pressure. The bladder stores urine, the ureters transport urine from the kidneys to the bladder, and the urethra carries urine out of the body. In short, the kidneys carry out the central job of urine formation and body-wide regulation, making them the primary organ in this system.