What is the role of the nephron in the human body?

The nephron plays a crucial role in the human body primarily for its function in the renal system, specifically in filtering blood and forming urine. Each kidney contains approximately one million nephrons, which are the basic functional units responsible for maintaining fluid and electrolyte balance, as well as removing waste products from the bloodstream.

The process begins when blood enters the nephron, where filtration occurs at the glomerulus. In this process, plasma is filtered through the glomerular capillaries, allowing water and small solutes to pass while preventing larger molecules, such as proteins, from entering the filtrate. The result is a fluid called glomerular filtrate, which then proceeds through the renal tubules of the nephron.

As the filtrate travels through various segments of the nephron, such as the proximal convoluted tubule, loop of Henle, and distal convoluted tubule, additional reabsorption and secretion processes occur. Essential substances such as glucose, certain ions, and a considerable amount of water are reabsorbed back into the bloodstream. Meanwhile, waste substances and excess ions are secreted into the tubule, ultimately forming urine. This urine is then collected in the renal pelvis and transported to the bladder for excretion.