THE STOMACH. 565 



a crude state." The free acid of this fluid is the hydro- 

 chloric,* which, in combination with a peculiar animal 

 matter, called pepsin, is believed to constitute the proper 

 digestive principle. So potent is this principle represented, 

 that the sixty-thousandth part, in acidulated water, im- 

 parts to it digestive properties. 



The mucous coat also presents numerous rugge, folds or 

 wrinkles, which are irregular in their course, size, and 

 shape. The most prominent run in the long diameter of 

 the stomach, and nearly parallel. They are most distinct 

 about the pylorus. The texture of this coat is soft, easilj 

 torn, and loose. It is covered by epithelium, which is more 

 delicate, thinner, and softer, than that of the pharynx or 

 O3sophagus with which it is continuous, and, unlike these, 

 has the cylindrical instead of the laminated form. 



Where the stomach ends in the duodenum, the mucous 

 coat forms a fold called the pyloric valve; around this valve 

 the circular fibres of the muscular coat collect in the form 

 of a bundle, and constitute a sphincter muscle, upon which 

 depends all the efficacy of this valve in closing the open- 

 ing from the stomach into the duodenum. About both ex- 

 tremities of the stomach, the mucous -coat contains glands 

 which resemble those of Brunner. They are thought to 

 furnish mucus. 



Blood-vessels of the Stomach. The arteries are the gastric 

 or coronary, which comes from the cardiac axis, and runs 

 along the upper curvature ; the right and left epiploic, and 

 the vasa brevia, which come from- the hepatic and splenic 

 arteries. The epiploic arteries run along the greater curv- 

 ature, anastomosing and radiating in every direction, while 

 the vasa brevia, which are five or six small branches from 

 the splenic, pass to the left or greater end of the stomach. 



The corresponding veins enter into the vena portarum. 

 The nerves are the pneumo-gastric, and the sympathetic. 

 The former form a plexus around the cardiac orifice and ex- 



* Lehmann, Bernard, and Baneswil affirm that the free acid is lactic. Prout, 

 Dunglison. Enderlin, Leibig, Bence Jones, and Graham, say that it is the. 

 hydrochloric. 



