The diaphragm is the primary muscle used in the process of inspiration, or inhalation. It is a dome-shaped sheet of muscle that is inserted into the lower ribs. Lying at the base of the thorax (chest), it separates the abdominal cavity from the thoracic cavity. read more
A: The diaphragm is a sheet of muscle that stretches like a dome over the organs of the upper abdomen and serves as a boundary between the abdominal cavity and the thoracic. It separates the lungs from the main body cavity and, together with the ribs, forms a seal that allows the lungs to inflate as part of the process of respiration. read more