Muscle of left hemidiaphragm

The muscular fibers of the left part of diaphragm (left hemidiaphragm) may be grouped according to their origins into three parts:

• The lumbar part arises from aponeurotic arches, the left medial arcuate ligament and the left lateral arcuate ligament (also termed lumbocostal arches), and from the lumbar vertebrae by the left crus of diaphragm.

• The costal part arises from the inner surfaces of the cartilages and adjacent portions of the lower six ribs on either side, interdigitating with the Transversus abdominis

• The sternal part arises by two fleshy slips from the back of the xiphoid process