The diaphragm is a muscular-fibrous structure located between the thoracic and abdominal cavities, its peripheral part is muscular and its central part is transposed into a tendon membrane. Its main function is to separate the thoracic and abdominal cavities, as well as to participate in respiration and increase abdominal pressure. The diaphragm has three starting points: the starting point of the sternum is located behind the glabella; the starting point of the rib section is located on the inner surface of the 6th rib; the starting point of the lumbar section is located in front of the 2nd and 3rd lumbar vertebrae and the transverse process of the 1st lumbar vertebra. There are three fissures in the diaphragm: 1) the aortic fissure, in which the aorta and the thoracic duct pass. 2) the esophageal fissure, in which the esophagus and the vagus nerve pass. 3) the vena cava fissure, in which the inferior vena cava and the phrenic nerve pass. The diaphragm is controlled by the will, which means that it can control its movement. When the diaphragm contracts it can assist in inspiration and when the diaphragm diaphragms it can assist in expiration. When the diaphragm and the abdominal muscles contract together, they increase abdominal pressure, which helps with bowel movements and childbirth during pregnancy, etc.