What is the basic functional unit of the kidney called?

The basic functional unit of the kidney is the nephron, which plays a crucial role in filtering blood and forming urine. Each kidney contains approximately one million nephrons, which consist of several key components that work together to perform essential functions such as filtration, reabsorption, and secretion.

The nephron begins with the renal corpuscle, which includes the glomerulus—a network of capillaries where the filtration of blood takes place. This initial stage is followed by the renal tubules, where substances are reabsorbed into the bloodstream or secreted into the urine. The overall process ensures that waste products and excess substances are removed from the body, while retaining vital compounds and water.

The other terms, such as alveolus and acinus, refer to structures in different organs; the alveolus is a functional unit of the lungs, and the acinus is typically associated with the glandular structure in organs like the pancreas or salivary glands. The glomerulus, while a critical component of the nephron, is not the nephron itself but rather part of the nephron's structure. Thus, while the glomerulus is important for the kidney's function, it does not encompass the complete array of functions performed by the nephron