What is the primary functional unit of the kidney responsible for filtering blood?

The primary functional unit of the kidney that is responsible for filtering blood is the nephron. Each nephron plays a crucial role in the kidney's ability to remove waste and excess substances from the blood while helping to maintain fluid and electrolyte balance in the body. The nephron comprises a glomerulus and a renal tubule, working together to filter blood, reabsorb essential nutrients, and excrete waste as urine.

The glomerulus, while vital as part of the nephron, is specifically the tiny ball of capillaries where initial filtration occurs, but it does not perform the full range of kidney functions on its own. The renal pelvis serves as a funnel for urine flowing from the kidneys to the ureters and does not partake in blood filtration directly. The ureter transports urine from the kidneys to the bladder, also lacking any filtering ability. Collectively, these structures support the nephron’s function, but the nephron remains the central unit responsible for blood filtration.