Diaphragm Muscles of respiration

the diaphragm major muscle responsible breathing. thin, dome-shaped muscle separates abdominal cavity thoracic cavity. during inhalation, diaphragm contracts, centre moves caudally (downward) , edges move rostrally (upward). compresses abdominal cavity, raises ribs upward , outward , expands thoracic cavity. expansion draws air lungs. when diaphragm relaxes, elastic recoil of thoracic wall causes thoracic cavity contract, forcing air out of lungs.

the diaphragm involved in non-respiratory functions, helping expel vomit, faeces, , urine body increasing intra-abdominal pressure, , preventing acid reflux exerting pressure on esophagus passes through esophageal hiatus.