THE MUSCLES. 153 



the pleura), 2" long, 3 to 4"' broad. The crura then pass into the tendinous 

 centre. 



S. Crura Medifi arising from the sides of the second lumbar vertebra, or 

 from lig. intervertebrale, uniting above with the internal and external crura, 

 passing into the centr. lendin. become perforated by 2V. splanchnicus minor. 

 Between the central and internal crura pass through : Nn. splanchnid maj. 

 between the central and external: Nn. sympathid, Vena hemiazygos upon the 

 left and Vena azygos sometimes upon the right side. 



y. Crura externa, very short, arise from the first lumbar vert, (side of the 

 body) ; are united with lig. vertebro-costale before in. psoas, and quadrat, lumb., 

 losing themselves in the Centr. tendineum. 



b. Pars costalis (and sternalis), see under "Attachments." 

 Upon either side six fleshy heads from the rib cartilages and two 

 from the Proc. ensiformis pass inwards towards the Cent, ten- 

 dineum, which on the four inferior ribs are connected with m. 

 transv. abdom. Quite in front is found a small triangular inter- 

 space in which the Pleura and Peritonaeum come in contact. 



c. Centrum tendineum s. speculum ffelmontii, the central ten- 

 dinous portion, in shape like a trefoil leaf, is the most elevated 

 portion of the diaphragm, on a level with the fifth rib (at the 

 sternum), on the right side (over the liver) arched. In it, to the 

 right of the central line, we find iheforam. quadrilaterum (1 to 

 \k" diam.), through which aperture the V. cava inferior ascends 

 from the liver to the right ventricle of the heart, and the pleura 

 and peritonaeum come in contact. 



The superior (thoracic) surface, which in the foetus is much 

 more vaulted than after birth, when the lungs have fairly respired, 

 is covered by Pleura and Pericardium, and serves for the support 

 of the lungs and heart. 



The inferior surface is covered by peritonaeum, except at the 

 point corresponding to the obtuse border of the liver (lig. coronar. 

 hepat.}. On the right lies the liver, left the spleen and fundus of 

 the stomach. 



Use: the diaphragm, as it contracts, widens the thoracic and 

 diminishes the abdominal cavity. Thus in inspiration and in the 

 evacuation of the contents of the intestines. 



Nerves: phrenicus, branches of Vagus, lumbal, intercostal., sympathicus. 



Fascist Mdominales. 



267. 1. Fascia superficialis abdominis covers the anterior 

 surface of the abdominal muscles, is thin upon the fleshy parts, 

 firmly attached and thick upon the tendinous, particularly below 

 the navel, consists of fibro-cellular tissue interwoven with tendi- 

 nous and elastic fibres ; passing before the annul, abdomin. over 

 the spermatic cord into the Scrotum, it goes to join the fasc. 

 femor. superficialis. 



