The major functional part of the kidneys is the?

The major functional part of the kidneys is the nephron, which is the basic structural and functional unit of the kidney. Each kidney contains about a 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 consists of several components, including the renal corpuscle (which contains the glomerulus and Bowman's capsule) and the renal tubule, which further divides into segments such as the proximal convoluted tubule, loop of Henle, and distal convoluted tubule.

The nephron facilitates processes such as filtration, where blood is filtered in the glomerulus, and reabsorption, where water and valuable solutes are reclaimed, thereby maintaining the body’s fluid and electrolyte balance. Understanding the nephron's functions is crucial for realizing how kidneys regulate bodily functions, including blood pressure, electrolyte levels, and waste removal. This makes the nephron the most vital component regarding the kidneys' overall function.