What structures in the kidneys are responsible for the formation of urine?

The formation of urine primarily takes place in the nephrons, which are the functional units of the kidneys. Each kidney contains approximately one million nephrons, and they play a critical role in filtering blood, reabsorbing essential substances, and excreting waste products in the form of urine.

The nephron comprises several key components, including the glomerulus, Bowman’s capsule, and the renal tubules. The glomerulus is a network of capillaries that filters blood to produce filtrate. This initial filtrate then passes through various segments of the nephron, including the proximal convoluted tubule, loop of Henle, and distal convoluted tubule, where selective reabsorption and secretion processes occur. Eventually, this leads to the formation of urine, which is collected in the collecting ducts before being excreted.

While the glomeruli are involved in the filtration process, they are not the entirety of the urine-forming mechanism. Renal arteries are responsible for supplying blood to the kidneys, and the collecting ducts are involved in the final concentration and transport of urine to the renal pelvis. However, the complete urine formation process is a function of the nephron as a whole. Therefore, recognizing the nephron as