76o 



A MANUAL OF ANATOMY 



cave behind. It is divided into three lobes or alae, right, middle, 

 and left, of which the right is the largest, and the left the smallest 

 and narrowest. The separation into lobes is indicated by two 

 small notches situated in the course of the anterior convex 

 border. 



The diaphragm presents three foramina, namely, aortic, caval, 

 and oesophageal. 



The aortic opening is situated in the middle line between the 

 upper portions of the crura, and in front of the disc between the 

 bodies of the twelfth thoracic and first lumbar vertebrae. It is 

 bounded on either side by a crus, in front by the middle arcuate 

 ligament, and behind by the anterior common ligament of the 



Central Tendon 

 I 



L I 



V CEsophageal Opening 

 Right Crus ' > Aortic Opening 



Ixft Crus 



Fig. 326, — The Diaphragm (Superior View) 

 (After L. Testut's "Anatomic Humaine "). 



vertebral column. It is therefore not really an opening in the 

 diaphragm, but is situated behind it. It transmits the aorta, 

 thoracic duct, and right azygos vein, in this order from left to 

 right. 



The caval opening (foramen quadratum) is situated in the central 

 tendon close to its posterior border, and at the junction of the right 

 and middle lobes. It is somewhat four-sided with rounded angles, 

 and transmits the inferior vena cava and some of the deep lymphatics 

 of the liver. 



The oesophageal opening is situated in the fleshy part of the 

 muscle. It is elliptical, and lies in front, and a little to the left, of 

 the aortic opening, being separated from it behind by the inner 

 decussating fibres of the crura. It transmits the oesophagus, the 



