ABDOMINAL CAVITY 



385 



arches ; posteriorly, it springs by two powerful, partly fleshy 

 and partly tendinous processes, called the crura, from the 

 bodies of the upper three lumbar vertebrae, and, on each side 

 of those, from two ligamentous arches, termed the lumbo- 

 costal arches (O.T. ligamenta arcuatd) (Fig. 184). 



Anterior Attachment. The sternal origin consists of two 

 fleshy slips which spring from the back of the xiphoid process. 

 These are separated from each other by a narrow linear 

 interval filled with areolar tissue, and comparable with the 



Central tendon (median part) 



Inferior vena cava \_ 



Aorta 



Central tendon 

 (right part) 

 Greater splanchnic 

 nerve 



Sympathetic trun 



Central tendon 

 eft part) 



Med. lumbo-costal arch 



Lateral lumbo-costal arch ' ! ~\ tl \\ 9 



th thoracic nerve * Efif/T/I & oasminor 



Quadratus lumborum 



FIG. 184. Semi-diagrammatic View of the Attachments of the 

 Diaphragm. 



i. Sternal origin (left). I 8. Medial lumbo-costal arch (left). 



2-7. Costal origins (left). | 9. Lateral lumbo-costal arch (left). 



10. Tendinous parts of the crura (left and right). 



wider interval, in the median plane behind, which separates 

 the two crura of the diaphragm. 



Lateral Attachments. The costal origin consists of six 

 pointed and fleshy slips which spring from the deep surfaces 

 of the lower six costal cartilages on each side. They inter- 

 digitate with the digitations of the transversus abdominis. 

 The sternal and costal origins of the diaphragm, on each side, 

 are separated by a small triangular interval in which the 

 pleural and peritoneal membranes are separated from each 

 other merely by some loose areolar tissue. Through the gap 

 the superior epigastric branch of the internal mammary 

 artery descends into the abdominal wall. 



VOL. II 25 



