The major organs of the excretory system are the skin, the lungs, the kidneys, the liver, the urinary system and the large intestine. These organs function to eliminate waste and excess materials from the body, but the excretory system doesn't have a formal anatomical classification.
The skin is the largest organ of the body, and it eliminates body waste through sweat. This helps to regulate the body's temperature, and it is a minimal part of the excretory system. When a person exhales, the lungs expel carbon dioxide from the blood, so respiration is a function of the excretory system.
The kidneys, bladder and urethra are part of the urinary system, and in combination they rid the blood of excess nitrogen, urea, salts and water in the form of urine. The liver performs two functions for the excretory system. First, it breaks down toxins and transforms them, such as turning ammonia into urea, which are then excreted through the kidneys as urine. The liver also makes bile, which breaks down fat. Bile is then stored within the gallbladder, and it is released in the small intestine where it breaks down fat and ethanol.
The large intestine removes any excess water from waste as it travels through the intestine. The remaining solid waste is then excreted.