Diaphragm is primary organ of respiration. It is a thin dome-shaped musculomembranous muscle that separates the thoracic cavity from the abdominal cavity.
There are openings in the diaphragm through which oesophagus, blood vessels, and nerves pass.
It plays an important role in respiration. The diaphragm contracts with each inspiration, becoming flattened downward and thus increasing the volume of the thoracic cavity. With each expiration it relaxes and is restored to its dome-shaped.
