VOMITING. 325 



into the lungs, the contraction of the diaphragm drags in the lower ribs 

 and presses on the stomach, and at the same time air is drawn into the 

 pharynx and into the oesophagus. After a few ineffectual efforts of this 

 description, a sudden, violent expiratory contraction of the abdominal 

 muscles takes place, accompanied by a contraction of the diaphragm. 

 The stomach is thus compressed between the abdominal muscles and 

 diaphragm. Immediately before this effort the cardiac orifice of the 

 stomach is brought close up to the opening in the diaphragm by a 

 contraction of the longitudinal fibres at the lower end of the oesophagus, 

 and is dilated by the contraction of these fibres and the relaxation of 

 its sphincter. Thus a way is opened for the escape of the contents of 

 the stomach, and these are pressed out by the contraction of the 

 abdominal muscles, and to some extent by that of the muscular wall 

 of the stomach itself, and are ejected forcibly up the oesophagus and out 

 through the mouth. At the same time the soft palate is raised, and 

 the posterior pillars of the fauces approximated, so as to shut off, though 

 in many cases ineffectually, the passage through the nose. A strong 

 expiratory effort is made immediately after the passage of the gastric 

 contents, in order to prevent any remnants of the vomit passing into the 

 larynx. 



If the movements of the stomach be observed, either by opening the 

 abdomen (Openchowski), or by means of the Kontgen rays (Cannon) after the 

 administration of apomorphine, the first change noticed is an extreme relaxa- 

 tion of the cardiac end. Then a deep constriction starts about 3 cms. below 

 the cardia, and, growing in strength, moves towards the pylorus. On reaching 

 the transverse band, this contracts tightly, and a wave of contraction passes 

 over the antrum. This is followed by ten or twelve other waves, and then the 

 firm contraction at the beginning of the antrum divides the stomach into two 

 parts, one tightly contracted, and the other, the fundus, relaxed and flaccid. 

 A sudden contraction of the diaphragm and abdominal muscles, accompanied 

 by the opening of the cardiac orifice, now forces the gastric contents into and 

 through the oesophagus. 



During vomiting tnere is generally a discharge of bile from the gall 

 bladder into the duodenum. A little of this may be pressed through 

 the closed pyloric orifice, so that, after the emptying of the stomach, 

 the later efforts of vomiting may bring up a little bile-stained mucus. 



It was long a subject of discussion whether the contraction of the 

 stomach or that of the abdominal wall was the more essential factor in 

 the act of vomiting. Magendie l thought he had decided the question 

 when he pointed out that vomiting might be produced by the injection 

 of tartar emetic into the blood, even after the stomach had been replaced 

 by a bladder. It was shown subsequently, however, that this was only 

 true if the bladder were tied into the lower end of the oesophagus. If 

 the cardiac orifice be left intact, and merely the greater part of the 

 stomach replaced by the bladder, vomiting cannot be brought about. 2 

 This fact proves that there are two necessary factors in vomiting, 

 namely, active dilatation of the cardiac orifice and compression of the 

 stomach. So far as the latter event is concerned, it is probable that 

 Magendie was correct, since, in a curarised animal, it is impossible to 



1 "Memoire sur le vomissement," Paris, 1813. Cited by S. Mayer. 



2 Tanbini Omodei, Ann. univ. di med. e chir., Milano, 1824, (S. Mayer) ; Sclriff, 

 Untersuch. z. NaturL d. Mensch. u. d. Thiere, 1867, Bd. x. S. 353. 



