DIAPHRAGM. 



219 



with the tendon of the lesser muscle opposite the body of the 

 second. 



The tendinous centre of the diaphragm is shaped like a trefoil leaf, 

 of which the central leaflet points to the ensiform cartilage, and is the 

 largest ; the lateral leaflets, right and left, occupy the corresponding 



Fig, 94.* 



* The under or abdominal side of the diaphragm. 1, 2, 3. The greater mus- 

 cle ; the figure 1 rests upon the central leaflet of the tendinous centre ; the 

 number 2 on the left or smallest leaflet ; and number 3 on the right leaflet. 

 4 The thin fasciculus which arises from the ensiform cartilage ; a small trian- 

 gular space is left on either side of this fasciculus, which is closed only by the 

 serous membranes of the abdomen and chest. 5. The ligamentum arcuatum 

 externum of the left side. 6. The ligamentum arcuatum internum. 7. A 

 small arched opening occasionally found, through which the lesser splanchnic 

 nerve passes. 8. The right or larger tendon of the lesser muscle ; a muscular 

 fasciculus from this tendon curves to the left side of the greater muscle between 

 the oesophageal and aortic openings. 9- The fourth lumbar vertebra. 10. The 

 left or shorter tendon of the lesser muscle. 11. The aortic opening occupied 

 by the aorta, which is cut short off. 12. A portion of the oesophagus issuing 

 through the cesophageal opening ; in this figure the oesophageal opening is 

 tendinous at its anterior part, a structure which is not uncommon. 13. The 

 opening for the inferior vena cava, in the tendinous centre of the diaphragm. 

 14. The psoas magnus muscle passing beneath the ligamentum arcuatum 

 internum ; it has been removed on the opposite side to shew the arch more 

 distinctly. 15. The quadratus lumborum passing beneath the ligamentum 

 arcuatum externum ; this muscle has also been removed on the left side. 



