Why are organs in the human body made up of several types of tissues?

Organs are structures made up of two or more primary types of tissue, arranged in varying proportions and combinations to perform a specific function or range of functions.

The lungs are one example of an organ made up of all four types of tissue. The tissues that make up the lungs come together to pull air out of the atmosphere, exchange oxygen from the air we breathe for carbon dioxide from the blood. The alveoli of the lungs are covered with epithelial tissue; the airway walls contain smooth muscle; the lungs also contain nerve tissue and connective tissue.