

MOVEMENTS OF THE STOMACH. 231 



of considerable size, such as stones, have been passed by the anus after having 

 been introduced into the stomach ; but observations have shown that masses 

 of digestible matter are passed by the movements of the stomach to the 

 pylorus, over and over again, and that they do not find their way into the 

 intestine until they have become softened and more or less disintegrated. 



The contractions of the walls of the stomach are of the kind character- 

 istic of the non-striated muscular fibres. If the finger be introduced into 

 the stomach of a living animal during digestion, it is gently but rather firmly 

 grasped by a contraction, which is slow and gradual, enduring for a few 

 seconds and as slowly and gradually relaxing and extending to another part 

 of the organ. The movements during digestion present certain differences 

 in different animals; but there can be no doubt that the phenomenon is 

 universal. In dogs, when the abdomen is opened soon after the ingestion of 

 food, the stomach appears pretty firmly contracted on its contents. In a case 

 reported by Todd and Bowman, in the human subject, in which the stomach 

 was very much hypertrophied and the walls of the abdomen were very thin, 

 the vermicular movements could be distinctly seen. These movements were 

 active, resembling the peristaltic movements of the intestines, for which, in- 

 deed, they were mistaken, as the nature of the case was not recognized during 

 life. No argument, therefore, seems necessary to show that during digestion, 

 the stomach is the seat of tolerably active movements. 



A peculiarity in the movements of the stomach, which has been repeatedly 

 observed in the lower animals, particularly dogs and cats, and in certain cases 

 has been confirmed in the human subject, is that at about the junction of 

 the cardiac two-thirds with the pyloric third, there is frequently a transverse 

 band of fibres so firmly contracted as to divide the cavity into two almost 

 distinct compartments. It has also been noted that the contractions in the 

 cardiac division are much less vigorous than near the pylorus ; the stomach 

 seeming simply to adapt itself to the food by a gentle pressure as it remains 

 in the great pouch, while in the pyloric portion, divided off as it is by the 

 hour-glass contraction above mentioned, the movements are more frequent, 

 vigorous and expulsive. 



As the result chiefly of the observations of Beaumont, the following may 

 be stated as a summary of the physiological movements of the stomach in 

 digestion : 



The stomach normally undergoes no movements until food is passed into 

 its cavity. When food is received, at the same time that the mucous mem- 

 brane becomes congested and the secretion of gastric juice begins, contrac- 

 tions of the muscular coat occur, which are at first slow and irregular, but 

 become more vigorous and regular as the process of digestion advances. After 

 digestion has become fully established, the stomach is generally divided, by 

 the firm and almost constant contraction of an oblique band of fibres, into a 

 cardiac and a pyloric portion ; the former occupying about two-thirds, and 

 the latter, one-third of the length of the organ. The contractions of the 

 cardiac division of the stomach are uniform and rather gentle ; while in the 

 pyloric division, they are intermittent and more expulsive. The effect of the 



