What structural unit of the kidney is responsible for filtering blood?

The nephron is the fundamental structural and functional unit of the kidney responsible for filtering blood. Each nephron consists of a renal corpuscle and a renal tubule, and it plays a key role in the process of urine formation. Within the renal corpuscle, the glomerulus—a network of capillaries—filters blood, allowing water, ions, and small molecules to pass while retaining larger molecules like proteins and blood cells. This filtrate then enters the renal tubule, where further processing occurs for reabsorption and secretion, ultimately leading to urine formation.

While the glomerulus is crucial to the filtration process, it is part of the nephron, which encompasses both the glomerulus and the associated tubules that modify the filtrate. The collecting duct and the renal pelvis, on the other hand, serve distinct functions within the kidney's overall structure. The collecting duct is involved in the concentration of urine and the reabsorption of water, while the renal pelvis acts as a funnel to direct urine from the kidney to the ureter. Thus, identifying the nephron as the complete unit responsible for the overall filtration and subsequent processing of blood affirms its significance in kidney function.