- Development of the thoracic diaphragm
- Septum transversum – central tendon
- Pleuroperitoneal membrane – muscular diaphragm
- Lateral body wall – muscular diaphragm
- Dorsal mesoesophagus – crura of the diaphragm
- Developmental anomalies of the thoracic diaphragm
- Bochdalek Hernia (Posterolateral defect of the diaphragm (Foramen of Bochdalek)
- Defective formation and or fusion of the pleuroperitoneal membrane with the other three parts of the diaphragm resulting in a large opening in the posterolateral diaphragm
- Most common on the left
- Congenital Hiatal hernia
- Herniation of the fetal stomach through the oesophageal hiatus
- Morgagni hernia (Retrosternal/Parasternal hernia)
- Herniation of the intestines or heart through the foramen of Morgagni into the pericardial sac or epigastrium respectively
- Eventration of the diaphragm
- Superior displacement of viscera into a sac-like diaphragmatic part due to defective musculature as the muscular tissue from the body wall fails to extend into the pleuroperitoneal membrane of the affected side
- Accessory diaphragm
- Most often on the right side and associated with lung hypoplasia and other respiratory complications
- Bochdalek Hernia (Posterolateral defect of the diaphragm (Foramen of Bochdalek)



