552 



THE DIAPHRAGM. 



FIG. 173. 



is generally divided into two portions, called the greater 

 and lesser diaphragm. 



The greater arises 

 fleshy from the pos- 

 terior part of the 

 ensiform cartilage, 

 from the inner sur- 

 face of the cartilages 

 of the seventh true, 

 and all the false rihs, 

 and for some extent 

 fiom the osseous por- 

 tion of the last two 

 rihs. This origin, in- 

 cluding almost a cir- 

 cle, indigitates with 

 the transversalis 

 muscle. Between the ensiform cartilage and the ribs there 

 is a triangular space containing cellular and fatty matter, 

 and giving passage to the internal mammary vessels, in 

 which there is occasionally found an opening through 

 which some of the abdominal viscera pass into the chest, 

 constituting hernia. From the circumference of this 

 greater muscle of the diaphragm, the fibres radiate or con- 

 verge to a central tendon called the cordiform tendon. This 

 tendon, which has been compared to the heart of a playing 

 card, is a tendiiious expansion of considerable extent, and 

 of silvery whiteness, having its notch toward the spine and 

 its apex to the sternum. All round its circumference the 

 muscular portion of the diaphragm is attached to it. The 

 lesser diaphragm consists of two crura, right and left, which 

 are situated upon each side of the lumbar vertebrae. The 



FIG. 173 represents the Diaphragm or superior wall of the Abdomen. 1 2 

 3 Greater muscle of the diaphragm. 4 Space where hernia sometimes occurs. 

 5 Ligamentum arcuatum. 6 Origin of psoas-magnus. 7 Opening for lesser 

 splanchnic nerve. 8 One of the crura of the diaphragm. 9 Fourth lumbar 

 yertebra. 10 Another of the crura of the diaphragm. 11 Opening for the 

 aorta. 12 Opening for the oesophagus. 13 Opening for the ascending cava* 

 14 Psoas magnus. 15 Quadratus lumborum. 



