THE 8TCMACH 



1271 



nth Thoracic V. 



fst Lumbar V.- 



FIG. 993. Form and topography of the stom- 

 ach when empty and contracted, as seen imme- 

 diately after death in an executed individual. 



The shape and position of the stomach are so greatly modified by changes 

 within itself and in the surrounding organs that no one form can be described 

 as typical. The chief modifications are determined by (1) the amount of the 

 stomach contents, (2) the stage which the digestive process has reached, (3) the 

 degree of development or functional power 

 of the gastric musculature, and (4) the 

 condition of the adjacent intestines. 



When empty and contracted, as after a 

 period of rest, 1 the stomach is sickle- or 

 sausage-shaped, as shown in Fig. 993. At 

 an early stage of gastric digestion the 

 stomach commonly consists of two seg- 

 ments (a) a large, globular portion on the 

 left, and (6) a narrow tubular portion on 

 the right, corresponding to the fundus and 

 pyloric portions, and forming an angle 

 with each other, the axis of the fundus 

 being directed downward and inward while 

 the pyloric portion curves upward and to 

 the right. 



The stomach presents two openings, two borders or curvatures, and two sur- 

 faces. 



Openings. The opening by which the oesophagus communicates with the 

 stomach is known as the cardiac orifice, and is situated at the level of the eleventh 

 thoracic vertebra, corresponding to the seventh left chondrosternal junction. 

 The short intra-abdominal portion of the oesophagus (antrum cardiacum) is 

 conical in shape and curved sharply to the left, the base of the cone being continu- 

 ous with the cardiac orifice of the stomach. The right margin of the oesophagus 

 is continuous with the lesser curvature of the stomach, while the left margin joins 

 the greater curvature at an acute angle, the incisura cardiaca. 



The pyloric orifice communicates with the duodenum, and its position is indi- 

 cated on the surface by a circular groove, the duodenopyloric constriction. This 



orifice lies to the right of the middle line 

 at the level of the upper border of the first 

 lumbar vertebra; it may be from one to 

 two inches to the right of the middle 

 line, depending upon the degree of dis- 

 tention of the stomach. Its position on 

 the ventral surface of the body would be 

 indicated by a point in the transpyloric 

 plane (see p. 1243) about one inch to 

 the right of the middle line. 



Curvatures. The lesser curvature (cur- 

 vatura ventriculi minor), extending be- 

 tween the cardiac and pyloric orifices 

 forms the right or posterior border of the 

 stomach. It descends as a continuation 

 of the right margin of the oesophagus 



in front of the left crus of the Diaphragm, and then, turning to the right, it crosses 

 the first lumbar vertebra and ends at the pylorus. Nearer its pyloric than its 

 cardiac end is a well-marked notch, the incisura angularis, which varies somewhat 

 in position with the state of distention of the viscus, it serves to separate the stomach 



1 An opportunity to view this condition is given by the immediate examination of the organ in situ iu exe- 

 cuted criminals who have not eaten for some time. 



Pylori? vestibule 



Antrum cardiacum 



Incisura angularis S 



Pyloru, 

 Pyloric canal 

 Sitlcus intermedius 



FIG. 994.- 



-Outlines of the stomach showing its 

 anatomical landmarks. 





