| Crus of diaphragm | |
|---|---|
 Thediaphragm. Under surface. (Left crus and right crus are at bottom center.)+ | |
| Details | |
| Identifiers | |
| Latin | crus sinistrum diaphragmatis, crus dextrum diaphragmatis |
| Anatomical terminology | |
Thecrus of diaphragm (pl.: crura), refers to one of twotendinous structures that extends below thediaphragm to thevertebral column. There is a right crus and a left crus, which together form a tether for muscular contraction. They take their name from their leg-shaped appearance –crus meaningleg in Latin.
The crura originate from the front of the bodies andintervertebral fibrocartilage of thelumbar vertebrae. They are tendinous and blend with theanterior longitudinal ligament of thevertebral column.
The medial tendinous margins of the crura pass anteriorly and medialward, and meet in the middle line to form an arch across the front of theaorta known as themedian arcuate ligament; this arch is often poorly defined. The area behind this arch is known as theaortic hiatus.
From this series of origins the fibers of the diaphragm converge to be inserted into thecentral tendon.
The fibers arising from thexiphoid process are very short, and occasionallyaponeurotic; those from the medial andlateral lumbocostal arches, and more especially those from the ribs and their cartilages, are longer, and describe marked curves as they ascend and converge to their insertion. The fibers of the crura diverge as they ascend, the most lateral being directed upward and lateralward to the central tendon.
The medial fibers of the right crus ascend on the left side of theesophageal hiatus, and occasionally a fasciculus of the left crus crosses the aorta and runs obliquely through the fibers of the right crus toward thevena caval foramen.
This article incorporates text in thepublic domain frompage 405 of the 20th edition ofGray's Anatomy(1918)
