Renal regulation refers to the processes by which the kidneys maintain the body's fluid and electrolyte balance. This involves filtering blood to remove waste products and excess substances, while reabsorbing essential nutrients and water. The kidneys play a crucial role in regulating blood pressure and maintaining the body's acid-base balance. The nephrons, the functional units of the kidneys, are responsible for these regulatory functions. They filter blood through a series of tubules, where substances are selectively reabsorbed or excreted. Hormones like aldosterone and antidiuretic hormone (ADH) also influence renal regulation by adjusting the reabsorption of sodium and water, respectively.