Diaphragm C3 - C5

Two parts - crural and costal

Crural:

From - L1,2,3 and the medial and lateral arcuate ligaments.
To - Central tendon.
Function: normally it displaces abdominal contents only.

Costal:

From - lower 6 ribs.
To - Central tendon.
Function: normally it displaces abdominal contents and elevates and expands lower rib cage. The extent of each depends on abdominal and thoracic compliance.