1006 DIGESTION 



antri pylori and corresponds to the point of origin of the peristaltic 

 movements of the pyloric end of this organ. It is also of interest to 

 note that this muscular band is more highly constricted in some 

 persons than in others, giving rise to the so-called hour-glass stomach. 

 While this condition may be inherited, it is more commonly caused by 

 excitations of the gastric mucosa, such as may arise in consequence of 

 erosions and ulcers. The outer longitudinal layer continues at the 

 cardia with the longitudinal fibers of the esophagus, and is heaviest 

 along the greater and lesser curvatures of the stomach. At the pylo- 

 rus it passes over into the longitudinal layer of muscle tissue of the 

 duodenum. 



Anatomically, therefore, the stomach may be divided into two 

 compartments, namely, into its pyloric portion or antrum pylori, 

 comprising about one-fifth of the entire organ, and its much larger 

 fundic portion and cardiac recess. This division also possesses a 

 correct physiological basis, because the antrum pylori is infinitely 

 more active than the fundus, so much so, in fact, that the latter is 

 commonly regarded as the reservoir of the former. A more thorough 

 study of these movements may be made with the help of the following 

 methods : 



(a) Observation of the manner in. which th^ gastric contents are discKarged 

 through a duodenal fistula. ^ 



(6) Introduction of a small rubber bag into the cavity of the stomach which is 

 connected with a recording tambour. 2 



(c) Inspection of the interior of the stomach through a fistulous opening 

 (Beaumont). 



{d) Observation of the stomach through a wound in the abdominal wall, a 

 piece of mica being inserted in tHe opening to protect the stomach against external 

 stimuli, 



(e) Observation of the excised stomach under proper conditions of moisture 

 and temperature. 3 



(/) Observation of the stomach by means of the Rontgen-rays after the inges- 

 tion of food containing subnitrate of bismuth.^ 



The empty stomach is small in size, but its walls cannot collapse, 

 because a thin layer of frothy material remains interposed between 

 them. This froth consists of mucus and a few cubic centimeters of 

 gastric juice. At this time, the intragastric pressure is zero. The 

 entrance of food then separates its walls more widely but chiefly those 

 of the cardia, because the newly swallowed material collects at first di- 

 rectly below the esophageal orifice. Here it may remain in a rela- 

 tively undisturbed condition for nearly an hour, salivary digestion 

 going on unhindredly during the interim. This fact is wiell illustrated 

 by the experiments of Griitzner,^ who fed rats successively with semi- 



1 Hirsch, Zentralbl. klin. Med., 1892. 



2 Ducceshi, Arch. itil. de Biol., xxvii, 1897, 61. 



3 Hofmeister and Stutz, Archiv fiir Exp. Path, und Pharm., xx, 1885, 1. 



* Roux and Balthasard, Compt. rend., 1897, and Cannon, Am. Jour, of Physiol. 

 i, 1898, 359, and xii, 1904, 387. 



^ Pfliiger's Archiv, cvi, 1905, 463. 



I 



