Organs in the human body: Functions, location, definition of organs. An organ is a structure that contains at least two different types of tissue functioning together for a common purpose. There are many different organs in the body: the liver, kidneys, heart, even your skin is an organ.Usually there is a main tissue and sporadic tissues.or example, main tissue in the heart is the myocardium, while sporadic are the nerves, blood, connective etc.. Functionally related organs often cooperate to form whole organ systems. There are 10 major organ systems in the human body. List of Organs in human body: 1  Heart. 2  Brain.