What is the main purpose of the nephrons in the kidneys?

The primary function of nephrons in the kidneys is to filter blood and reabsorb essential substances. Each nephron consists of a glomerulus, which filters blood to create a filtrate, and a renal tubule, where reabsorption of water, ions, and nutrients occurs. This process is crucial for maintaining homeostasis in the body by regulating concentrations of various substances and ensuring waste is excreted efficiently.

Through filtration, nephrons remove waste products, toxins, and excess substances from the bloodstream, which are then excreted as urine. At the same time, they reabsorb important materials such as glucose, certain ions, and water back into the bloodstream. The balance these processes maintain is essential for proper bodily function, impacting electrolyte levels, blood pressure regulation, and overall fluid balance.

In contrast, while the kidneys do play a role in hormone production, such as erythropoietin, this is not the main purpose of the nephrons themselves. Similarly, while the kidneys help regulate blood flow by affecting blood pressure and volume, this is part of a broader system of renal function rather than a direct role of nephrons. Storage of urine occurs in the bladder, not in the nephrons, which