crura of diaphragm (crus)

Structure

• musculotendinous bundles that arise from the anterior surfaces of the bodies of the superior 3 lumbar vertebrae, the anterior longitudinal ligament & the IV discs

• right crus:
  • larger & longer than the left crus
  • arises from the first three or four lumbar vertebrae
  • esophageal hiatus is a formation in the right crus

• left crus;
  • arises from the first two or three lumbar vertebrae

* The 2 diaphragmatic crura form borders of the retrocrural space.

More general terms

• diaphragm muscle