What are nephrons primarily responsible for in the kidneys?

Nephrons are the fundamental structural and functional units of the kidneys, and their primary role is to filter blood and form urine. As they filter fluids from the bloodstream, nephrons remove waste products, excess ions, and water, which helps maintain fluid and electrolyte balance in the body. This filtering process occurs through a complex series of steps involving glomerular filtration, tubular reabsorption, and tubular secretion.

While hormones are produced in the kidneys (the kidneys do synthesize hormones such as erythropoietin and renin), this is not the primary role of nephrons. Additionally, the kidneys do not serve as storage sites for waste; instead, waste products are eliminated from the body through urine. Regulation of body temperature is a function of the body's thermoregulatory systems, not something that nephrons are directly responsible for. Thus, the focus of the nephron's role is distinctly on filtering fluids from the bloodstream.