Urine is carried to the bladder in the ureter. Urination is under voluntary control of the external sphincter. An adult bladder can hold 0.5L of urine. Within the kidney, nephrons may extend into the renal medulla. Filtration in the glomerulus occurs because of a difference in diameter between the arterioles bringing blood in and the arterioles taking blood out.
Tubular reabsorption occurs in the distal tubule .
During tubular secretion, wastes that are actively secreted into the tubule may include drugs. Each drop of blood passes through a kidney 10 times a day. ADH is released when receptors in the hypothalamus detects an inappropriate osmotic level in the blood. A long loop of Henle is found in the kidneys of aquatic animals.