Nephrons are the functional units of the kidneys, and are responsible for filtering waste products from the blood, regulating electrolyte balance, and maintaining overall fluid balance in the body. Nephrons are located within the renal cortex and renal medulla of the kidneys.The renal cortex is the outermost layer of the kidney, and is where the majority of the nephrons are located. The renal medulla, or inner part of the kidney, contains a smaller number of nephrons. The renal medulla also contains the renal pyramids, which are responsible for producing concentrated urine.Each nephron is composed of a renal corpuscle, which is responsible for filtering the blood, and a renal tubule, which reabsorbs important electrolytes and water back into the bloodstream. The renal corpuscle is made up of a Bowman's capsule, which surrounds the glomerulus, a small bundle of capillaries where blood is filtered. The Bowman's capsule and glomerulus work together to filter the blood, removing waste products such as urea and creatinine, while allowing important molecules such as glucose and electrolytes to remain in the bloodstream.The renal tubules of the nephron are responsible for reabsorbing important substances back into the bloodstream, and regulating the balance of electrolytes and fluid in the body. The renal tubules are divided into several segments, each with specific functions. For example, the proximal tubule reabsorbs the majority of glucose, amino acids, and electrolytes, while the distal tubule plays a role in regulating blood pressure and maintaining the balance of electrolytes.Overall, nephrons are the functional units of the kidney, and are responsible for filtering waste products from the blood, regulating electrolyte balance, and maintaining overall fluid balance in the body. They are located in the renal cortex and renal medulla of the kidneys, and are composed of a renal corpuscle and a renal tubule, each with specific functions.