What is the primary function of the nephron?

• A. Transport urine from bladder
• B. Filter blood to form urine
• C. Store urine
• D. Reabsorb bile acids

Answer: (B)

The nephron’s primary job is to filter blood to form urine. Blood enters the glomerulus, where a filtrate of water, salts, glucose, and waste products is created while larger proteins and cells stay in the blood. This filtrate then moves through the renal tubules, where most water, electrolytes, and nutrients are reabsorbed back into the bloodstream, and waste products are secreted into the filtrate to be excreted as urine. The overall goal is to transform plasma into urine that can be eliminated from the body. Transporting urine from the bladder and storing urine are functions of the urinary tract and bladder, not the nephron, and reabsorbing bile acids is a liver-related process, not a primary nephron function.