In renal physiology, which structure is primarily responsible for performing the kidney's work of filtration and urine formation?

In renal physiology, which structure is primarily responsible for performing the kidney's work of filtration and urine formation?

• A. Glomerulus
• B. Nephron
• C. Renal pelvis
• D. Ureter

Answer: (B)

The nephron is the kidney’s functional unit that carries out urine formation. Filtration begins in the glomerulus, where plasma is filtered into Bowman's capsule, but the entire process of forming urine—filtration plus reabsorption and secretion along the tubules (proximal tubule, loop of Henle, distal tubule, collecting duct)—happens within the nephron. The renal pelvis and ureter merely collect and transport urine after it’s formed; they don’t perform filtration or urine formation. So the nephron best fits as the structure responsible for the kidney’s work of filtration and urine formation.

The nephron is the kidney’s functional unit that carries out urine formation. Filtration begins in the glomerulus, where plasma is filtered into Bowman's capsule, but the entire process of forming urine—filtration plus reabsorption and secretion along the tubules (proximal tubule, loop of Henle, distal tubule, collecting duct)—happens within the nephron. The renal pelvis and ureter merely collect and transport urine after it’s formed; they don’t perform filtration or urine formation. So the nephron best fits as the structure responsible for the kidney’s work of filtration and urine formation.