3 o8 ABDOMEN 



tures forwards and backwards the greater curvature being 

 at a slightly higher level than the lesser curvature; lastly, 

 there is a gradual but decided downward slope of the upper 

 surface from the fundus to the pylorus. 



The pyloric extremity of the empty stomach lies in the 

 transpyloric plane (Addison), either where the latter cuts the 

 median plane, or from half an inch to an inch to the right of 

 the median plane. The transpyloric plane is situated midway 

 between the upper margin of the manubrium sterni and the 

 upper margin of the symphysis pubis. 



The conditions which give rise to the position and form of the empty 

 stomach as described above are sufficiently obvious when the nature of the 

 chamber within the abdomen which is occupied by the organ is considered. 

 The roof of this chamber, formed by the liver and diaphragm, is more 

 resistant, more unyielding, than the floor, which is formed chiefly by the 

 transverse meso-colon, buoyed up by the movable coils of small intestine. 

 As the stomach becomes empty and contracted, the intestine, acted on by 

 the abdominal wall, rises up and presses it against the sloping visceral 

 surface of the liver, and the slope or gradual descent to the right, which is 

 so characteristic a feature of the upper surface of the empty stomach, is the 

 result. 



When the stomach becomes full, it may either retain the 

 horizontal position, which is characteristic of the organ when 

 it is empty, or it may assume a more or less oblique position. 

 In both cases, it acquires more space within the abdomen 

 by displacing neighbouring viscera, and the pylorus moves 

 to the right, but not as a rule more than 35 to 50 mm. (an 

 inch and a half to two inches) from the median plane. The 

 pylorus does not alter its position in a vertical direction ; it 

 maintains the same level within the abdomen. The position 

 of the cesophageal opening is only slightly affected by the 

 emptying or the distension of the stomach. It is placed 

 opposite the body of the tenth thoracic vertebra, and on the 

 surface of the body its situation may be indicated by placing 

 the ringer on the seventh costal cartilage of the left side 

 about one inch from the median plane. 



As the stomach fills it becomes more rounded in general 

 outline, and, should it assume the oblique position when full, 

 the fundus is directed upwards, whilst the surfaces look 

 forwards and backwards ; further, the part of the greater 

 curvature opposite the incisura angularis takes a median 

 position and occupies a lower level than any other part of 

 the stomach. It follows from this that the pyloric part 



