The human organs are also called hollow organs because they have an empty tube or pouch. Examples of hollow organs include the stomach, intestine, and the heart.The eye is an organ that is generally considered part of the nervous system.Other organ systems in the human body include the immune system and the lymphatic system.The small intestine is actually much longer than the large intestine.<span>Some scientists say that the liver performs as many as 500 different functions. </span>
