ABDOMINAL CAVITY 



437 



a thick ring of muscle fibres, the valvula pylori (O.T. pyloric 

 sphincter}, and in many cases by a distinct constriction due 

 to the contraction of the sphincter. The first part of the 

 intestine runs backwards from the pylorus to the upper part 

 or neck of the gall-bladder, \vhere it turns downwards and 

 disappears from view behind a portion of the large intestine 



Stomach 



Transpyloric 

 plane 



Subcostal plane 



- Umbilicus 



Intertubercular 

 plane 



Iliac colon 



Left lateral 

 \ plane 



FIG. 1 66. The Abdominal Viscera as seen from the front after removal of 

 the great omentum. The dark lines indicate the subdivision of the 

 abdominal cavity. (Birmingham.) 



called the transverse colon. To trace it further turn the 

 great omentum upwards over the lower part of the thoracic 

 wall and expose the area below and behind the omentum. 

 The central and greater portion of this area is filled with coils 

 of the small intestine, but at the lateral and upper borders 

 of the area portions of the large intestine are seen. 



A mere glance is sufficient to distinguish the small from 



i 28 a 



