Kidney Filtration Rate: Each kidney filters about 120 to 150 quarts (114 to 142 liters) of blood daily, producing about 1 to 2 quarts (0.9 to 1.9 liters) of urine.

Nephrons Are the Filters: The functional units of the kidney are called nephrons. Each kidney contains about one million nephrons, which are responsible for filtering waste products from the blood.

Blood Pressure Regulation: The kidneys play a crucial role in regulating blood pressure. They can release an enzyme called renin, which helps control blood pressure by influencing the volume of blood and narrowing blood vessels.

Urea Production: Urea, a waste product of protein metabolism, is the main component of urine. It's formed in the liver and transported to the kidneys for excretion.

Bladder Capacity: The average adult bladder can hold up to 16 to 24 ounces (about 500 to 700 milliliters) of urine, but it's possible for some bladders to hold even more.

Bladder Contraction Strength: The bladder is a muscular organ. When it's full, it can contract with a force of around 5.2 inches of water (13.2 centimeters of water) to expel urine.

Ureter Peristalsis: Urine moves from the kidneys to the bladder through tubes called ureters. This movement is aided by rhythmic, involuntary muscle contractions known as peristalsis.

Kidneys' Role in pH Balance: The kidneys help regulate the body's pH level by excreting hydrogen ions and reabsorbing bicarbonate from urine.

ADH and Water Conservation: The hormone antidiuretic hormone (ADH) helps regulate water balance in the body. When ADH levels are high, more water is reabsorbed by the kidneys, leading to concentrated urine.

Calcium Regulation: The kidneys help regulate calcium levels in the body. They can either reabsorb calcium to conserve it or excrete excess calcium in the urine.

Kidney Transplants: Kidney transplantation is a life-saving procedure for individuals with end-stage kidney disease. It's one of the most common and successful types of organ transplantation.

Glomerular Filtration Rate (GFR): GFR is a measure of how well the kidneys are filtering waste from the blood. It's an important indicator of kidney function.