GASTRIC JUICE, AND STOMACH DIGESTION. 145 



the empty stomach, but is acquired by it on being digested with 

 albuminoid substances. 



Another important action which takes place in the stomach, 

 beside the secretion of the gastric juice, is the peristaltic movement 

 of the organ. This movement is accomplished by the alternate 

 contraction and relaxation of the longitudinal and circular fibres 

 of its muscular coat. The motion is minutely described by Dr. 

 Beaumont, who examined it, both by watching the movements of 

 the food through the gastric fistula, and also by introducing into 

 the stomach the bulb and stem of a thermometer. According to 

 his observations, when the food first passes into the stomach, and 

 the secretion of the gastric juice commences, the muscular coat, 

 which was before quiescent, is excited and begins to contract act- 

 ively. The contraction takes place in such a manner that the food, 

 after entering the cardiac orifice of the stomach, is first carried to 

 the left, into the great pouch of the organ, thence downward and 

 along the great curvature to the pyloric portion. At a short distance 

 from the pylorus, Dr. B. often found a circular constriction of the 

 gastric parietes, by which the bulb of the thermometer was gently 

 grasped and drawn toward the pylorus, at the same time giving a 

 twisting motion to the stem of the instrument, by which it was 

 rotated in his fingers. In a moment or two, however, this constric- 

 tion was relaxed, and the bulb of the thermometer again released, 

 and carried together with the food along the small curvature of 

 the organ to its cardiac extremity. This circuit was repeated so 

 long as any food remained in the stomach ; but, as the liquefied 

 portions were successively removed toward the end of digestion, it 

 became less active, and at last ceased altogether when the stomach 

 had become completely empty, and the organ returned to its ordi- 

 nary quiescent condition. 



It is easy to observe the muscular action of the stomach during 

 digestion in the dog, by the assistance of a gastric fistula, artificially 

 established. If a metallic catheter be introduced through the fistula 

 when the stomach is empty, it must usually be held carefully in 

 place, or it will fall out by its own weight. But immediatelv upon 

 the introduction of food, it can be felt that the catheter is grasped 

 and retained with some force, by the contraction of the muscular 

 coat. A twisting or rotatory motion of its extremity may also be 

 frequently observed, similar to that described by Dr. Beaumont. 

 This peristaltic action of the stomach, however, is a gentle one, 

 and not at all active or violent in character. We have never seen, 

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