The main excretory organs in most vertebrate bodies are the kidneys, liver, large intestine, skin and lungs. According to The Merck Manual Home Edition, these organs belong to different systems but all have the function of removing waste from the body and depositing it in the environment.
The main excretory organs do not work alone. Each is part of a larger system that includes a number of other organs. The kidneys, for example, filter waste and excess water from the blood and deposit it through thin tubes called ureters into the urinary bladder for final disposal. The large intestine sits at the end of the digestive tract and is the final stop in the body for food matter. Lungs are primarily respiratory organs that use their large surface area to efficiently excrete molecular wastes secreted by the body's cells. This waste gas, carbon dioxide, is expelled with each breath. Skin sweats, and it secretes sebaceous oil as a protective barrier against the external environment, notes Wikipedia.
The liver is large and extremely complicated. According to Wikipedia, the liver works to detoxify potentially harmful chemicals that are present in the blood. It also secretes bile, which the small intestine uses to break down ammonia and other wastes into harmless substances.