Embryology of the Diaphragm
The diaphragm develops from four distinct embryological components. Failure of these to fuse correctly leads to congenital diaphragmatic hernia (CDH).
| Component | Developmental Role |
|---|---|
| Septum Transversum | Forms the central tendon of the diaphragm. |
| Pleuroperitoneal Membranes | From the posterolateral portions, the most common site for defects. |
| Dorsal Mesentery of Esophagus | Forms the crura of the diaphragm. |
| Body Wall (Muscular Ingrowth) | Contributes to the peripheral muscular portion. |
High-Yield Clinical Notes:
- Congenital Diaphragmatic Hernia (CDH): Usually occurs on the left side (due to earlier closure of the right pleuroperitoneal canal) through the foramen of Bochdalek.
- Innervation: The diaphragm is derived from cervical somites (C3, C4, C5). Remember: “C3, 4, 5 keep the diaphragm alive.”