56. (a) Describe the mechanism of urine formation in human excretory system. Draw a labeled diagram to illustrate your answer
Urine is formed in three main steps- glomerular filtration, reabsorption and secretion. It comprises 95 % water and 5% wastes such as ions of sodium, potassium and calcium, and nitrogenous wastes such as creatinine, urea and ammonia. Osmoregulation is the process of maintaining homeostasis of the body.