The main process of excretion case place in the

kidneys. The kidneys filter waste substances from the blood, such as urea, excess salts, and water, to form urine. This urine is then transported to the bladder through the ureters for storage until it is eventually eliminated from the body through the urethra. Other organs involved in excretion include the liver, which eliminates toxins from the body through bile production, and the lungs, which remove carbon dioxide through respiration.