Which component is primarily responsible for filtration of blood to form urine?

Which component is primarily responsible for filtration of blood to form urine?

• A. Nephron
• B. Medulla
• C. Ureter
• D. Bladder

Answer: (A)

The nephron is the functional unit of the kidney responsible for urine formation through filtration, reabsorption, secretion, and concentration. Filtration occurs in the renal corpuscle, where the glomerulus filters blood plasma into Bowman's space, allowing water and small solutes to pass while retaining blood cells and large proteins. This filtered fluid then moves through the tubules, where reabsorption and secretion fine-tune what becomes urine. The medulla helps establish the osmotic gradient needed for concentration, but it is not the site of filtration. The ureter and bladder simply transport and store urine, not form it.

The nephron is the functional unit of the kidney responsible for urine formation through filtration, reabsorption, secretion, and concentration. Filtration occurs in the renal corpuscle, where the glomerulus filters blood plasma into Bowman's space, allowing water and small solutes to pass while retaining blood cells and large proteins. This filtered fluid then moves through the tubules, where reabsorption and secretion fine-tune what becomes urine. The medulla helps establish the osmotic gradient needed for concentration, but it is not the site of filtration. The ureter and bladder simply transport and store urine, not form it.