The excretory system is the system of an organism 's body that performs the function of excretion, the bodily process of discharging wastes. The Excretory system is responsible for the elimination of wastes produced by homeostasis..The excretory system functions as the bulwark and balance to the digestive system. The primary excretory organs in the human body are the kidneys, ureters .The roles of the other excretory organs are summarized below: The large intestine eliminates solid wastes that remain after the digestion of food. The liver breaks down excess amino acids and toxins in the blood. The skin eliminates excess water and salts in sweat. The lungs exhale water vapor and carbon dioxide..