What is the primary function of a nephron?

The primary function of a nephron is to filter blood to produce urine. Nephrons are the microscopic functional units of the kidney, and they play a crucial role in the body's ability to maintain fluid and electrolyte balance. Each nephron is composed of a renal corpuscle and a renal tubule, which work together to filter waste products, excess substances, and toxins from the blood. The filtered fluid then undergoes processes of reabsorption and secretion, ultimately leading to the formation of urine, which is collected and sent to the bladder.

In contrast, the roles of storing urine, directing urine out of the bladder, and coordinating kidney functions are performed by other structures or systems in the urinary system, but they do not reflect the fundamental role of the nephron itself. The bladder stores urine, the urinary tract directs urine out of the body, and various regulatory mechanisms and hormones coordinate kidney functions, but it is the nephron specifically that carries out the filtration process leading to urine production.