THE STOMACH 



1153 



viduals, and in the same individual according to changes in physiological condition, 

 posture, etc. It is therefore difficult to give a concise and accurate description. 



The normal position of the stomach has long been disputed. It is generally 

 recognised that the long axis is oblique, extending from above downward, forward 

 and to the right. Some, however, especially among the older anatomists, have 

 maintained that the gastric axis normally approaches more nearly to the horizon- 

 tal type, with the pylorus but little below the cardia (approximately the position 

 shown in figs. 915, 916). Others, especially among the more recent anatomists, 

 have maintained that the axis of the stomach is normally more nearly vertical in 

 position (see fig. 1125, Section XIII). The results of an extended and careful 

 study, both in formahn-hardened bodies and by means of the Rcentgen-rays in the 

 living body, demonstrate that there is much variability in the position of the stom- 

 ach. Both the horizontal and the vertical types may occur as the extremes of 

 normal variation, but the more usual type is the intermediate oblique position. 

 The gastric axis, however, is not straight, but somewhat curved and bent in a 

 reverse L-shape. The larger cardiac portion is approximately vertical (especially 

 when the trunk is in the upright posture) the smaller pyloric portion more nearly 

 horizontal (figs. 895, 906, 918, 919). In^the empty stomach, the pylorus opens 

 into the duodenum from left to right. ^Tii distention, however, the pylorus is 

 carried in front of the duodenum. In extreme distention, it is carried to the 

 right and downward so as to open upward and to the left. 



Fig. 908. — ^Longitudinal Section of the Pyloric Portion of the Stomach. 

 ham, Trans. Roj'al Soc. Edinb., vol. 45.) 



Sphincteric cylinder 

 \ 

 Duodeno-pyloric constriction \ 



Pyloric orifice 



(Cunning- 



Duodenum Pyloric canal Sulcus intermedius Pyloric vestibule 



In surface relation (fig. 914), the stomach Ues within the left hypochondriac 

 and the epigastric regions. Often, however, especially when distended, it extends 

 into the umbilical and even the right hypochondriac region. When empty, it 

 usually hes almost entirely in the left half of the body, with the pylorus not more 

 than 1 cm. or 2 cm. to the right of the mid-sagittal plane. When distended, the 

 long axis of the stomach is lengthened and the pylorus is displaced 5 cm. or more 

 fo the right and downward. In distention, the stomach expands in all directions 

 ("except posteriorly), and does not appear to rotate as is sometimes stated. The 

 position of the stomach, especially when distended, also varies appreciably accord- 

 ing to the 'posture of the body. It sags downward when the body is in the upright 

 position, and to the right or left v.dien the body is placed on the corresponding 

 side. The cardia hes on the left side of the 10th or 11th thoracic vertebra, and 

 corresponds to a surface point behind the left 7th costal cartilage about 2.5 cm. 

 from its sternal end. The pylorus usually Hes opposite the right side of the 

 1st lumbal- vertebra, about midway between ensiform cartilage and umbiHcus, 

 or in AdcUson's ' transpyloric line,' midway between the suprasternal notch 

 and the symphysis pubis, when the body is recumbent; but descends to the 2d 

 or lower in upright posture. The Jundus corresponds to the left dome of the 



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