468 ABDOMEN 



forwards ; to its uppermost segment is attached the gastro- 

 phrenic ligament, to its left lateral segment the gastro-lienal 

 ligament, and to its lowest or anterior segment the greater 

 omentum. 



The stomach is not only curved from one end to the other but it is also 

 bent upon itself more or less acutely so that a notch or angular depression, 

 the incisura angularis, is produced in the lesser curvature (Fig. 180). 

 Advantage is taken of this notch to divide the organ, for descriptive 

 purposes, into a large cardiac part which lies to the left and a much smaller 

 pyloric part which lies to the right of the incisura. 



The cardiac 'part of the stomach is generally considered to consist of a 

 fundus and a body. An imaginary line drawn around the organ from the 

 cardiac orifice to a point on the greater curvature directly opposite is taken 

 as separating these portions of the stomach from each other. 



The short pyloric part of the stomach is composed of a pyloric canal and 

 a pyloric vestibule. The pyloric canal is a short, narrow, usually cylindrical 

 part, about one inch or one inch and a quarter long, which immediately 

 adjoins the duodeno-pyloric constriction. It thus constitutes the right 

 extremity of the stomach, and its thick muscular walls and its cylindrical 

 form give it a special character of its own. The pyloric canal is, as a rule, 

 directed backwards, and it is marked off from the pyloric vestibule by a 

 slight notch in the greater curvature termed the sulcus intermedius. The 

 pyloric vestibule lies to the left of the pyloric canal and the sulcus inter- 

 medius. It is wider than the pyloric canal, and its walls are not so thick. 



But there is also a physiological subdivision of the stomach. During 

 the process of active digestion the right half of the body of the stomach and 

 the whole of the pyloric portion, by the firm contraction of their walls, 

 assume a tubular form. In this tube a thorough mixture and trituration 

 of the food is effected by means of constriction waves which pass over it in 

 regular procession from left to right. The fundus and left half of the body 

 of the stomach maintain a saccular form, and constitute a passive reservoir 

 from which food is squeezed into the more active tubular part to take the 

 place of the material which intermittently escapes from the stomach into 

 the small intestine. 



When the stomach is empty it is questionable if it ever assumes during 

 life the flaccid, relaxed, and flattened form which is so frequently seen in the 

 dissecting-room, in subjects which have not been specially hardened. In 

 life, the healthy stomach, by contraction of its muscular coat, adapts itself 

 to its contents whether these be liquid, gaseous, or solid, and when empty 

 and contracted its walls become thick and firm. 



Position of the Stomach. When empty and contracted the 

 stomach lies more or less horizontally within the abdominal 

 cavity, it is placed within the left hypochondrium and the 

 left portion of the epigastrium. The organ is bent on itself 

 like a sickle and the fundus sinks downwards so that it comes 

 to look directly backwards ; the surfaces are directed upwards 

 and downwards and the curvatures forwards and backwards 



the greater curvature being at a slightly higher level than 



the lesser curvature ; lastly, there is a gradual but decided down- 

 ward slope of the upper surface from the fundus to the pylorus. 



