The diaphragm is a double-domed musculotendinous partition dividing the body cavity to the abdominal and thoracic cavities and serves as the chief respiratory muscle.
Location
The diaphragm reaches the 5th rib on the right side and 5th IC space on the left.
Divisions
The diaphragm consists of 3 parts:
- Sternal part
- Costal part
- Lumbar part
These three parts converge as a trifoliate (“three-leaves shaped”) at the central tendon, which is fixed to the pericardium.
Lumbar part
- Arises from medial and lateral lumbocostal arches (also known as the arcuate ligaments)
- The arches attach to the fascia of the psoas major and quadratos lumbarum respectively (medial arch — psoas major,