Normally the space between the sternal and costal origins of the diaphragmatic muscle is very small and only allows the superior epigastric vessels to enter from the thorax into the
anterior abdominal wall. However, very phragm. This is called parasternal her-rarely a small part of the diaphragmatic nia (or hernia of Morgagni). A peri-muscle fails to develop from the sep- toneal sac containing intestinal loops turn transversum and, thus, a defect is oftenly enters the chest through gap created in the anterior part of the dia- provided by the parasternal hernia.