There are almost 78 organs in a human body which vary according to their sizes, functions or actions. An organ is a collection of millions of cells which group together to perform single functions in a our body. The cells in these body organs are highly specialized and form for all the necessary actions for some specific time. Out of these 78 organs of a male or female body, skin is the largest organ with respect to its size and weight. The major organ in the body of human beings is the brain which is primarily responsible for performing all the functions and actions of the body.