MOVEMENTS OF THE STOMACH. 253 



There can be no doubt that division of both these nerves produces immediate and 

 grave disorder in the process of stomach-digestion, amounting, it is more than probable, 

 to complete arrest of the secretion of the gastric juice. Its secretion may be induced 

 again by local stimulation, but the quantity is always greatly diminished. Under these 

 circumstances, it is possible that very small quantities of food may be digested in the 

 stomach a day or two after the operation ; and, if the animal survive for a considerable 

 time, the secretion may be to a certain extent reestablished. Serious trouble in stomach- 

 digestion is produced by the paralysis of the muscular coats of the stomach consequent 

 upon section of both pneumogastrics. 



Movements of the Stomach. As the articles of food are passed into the stomach by 

 the acts of deglutition, the organ gradually changes its form, size, and position. When 

 the stomach is empty, the opposite surfaces of its lining membrane are in contact in 

 many parts and are thrown into numerous longitudinal folds. As the organ is distended, 

 these folds are effaced, the stomach itself becoming more rounded ; and, as the two ends 

 with the lesser curvature are comparatively immovable, the whole organ undergoes a 

 movement of rotation, by which the anterior face becomes superior and is applied to the 

 diaphragm. At this time the great pouch has nearly filled the left hypochondriac region, 

 the greater curvature looks anteriorly, and comes in contact with the abdominal walls. 

 Aside from these changes, which are merely due to the distention, the stomach under- 

 goes important movements, which continue until its contents have been dissolved and 

 absorbed or have passed out at the pylorus. But while these movements are taking 

 place, the two orifices are guarded, so that the food shall remain for the proper time 

 exposed to the action of the gastric juice. We have already noted the rhythmical con- 

 tractions of the lower extremity of the oesophagus, by which regurgitation of food is 

 prevented ; and the circular fibres, which form a thick ring at the pylorus, are constantly 

 contracted, so that, at least during the first periods of digestion, only liquids and that 

 portion of food which has been reduced to a pultaceous consistence can pass into the 

 small intestine. It is well known that this resistance at the pylorus does not endure in- 

 definitely, for indigestible articles of considerable size, such as stones, have been passed 

 by the anus after having been introduced into the stomach ; but observation has 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 broken down. 



The contractions of the walls of the stomach are of the kind characteristic 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. The movements during digestion undoubtedly present certain 

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

 sal. 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 Bow- 

 man, 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 intes- 

 tines, for which, indeed, they were mistaken, as the nature of the case was not recog- 

 nized during life. No argument, therefore, seems necessary to show that, during diges- 

 tion, 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 



