What are the 4 main structures of the excretory system?

The main organs of the excretory system are the kidneys, which filter nitrogen-based wastes from your blood. Accessory organs for the kidneys are the ureters, bladder, and urethra. Together these make up the urinary system.

Lungs remove carbon dioxide from your body. These are also part of the respiratory system.

The sweat glands of the skin get rid of wastes. The skin is also part of the integumentary system, and, through its sense of touch, is part of the senses of the nervous system.

The liver, which is also part of the digestive system, breaks down drugs and toxins for excretion. The liver also makes bile.

The large intestine, or colon, removes excess water from solid food wastes, which are then expelled through the anus in the form of feces.