SECTION IV 

 THE MOVEMENTS OF THE STOMACH 



THESE can be best studied by Cannon's method -that is, by direct 

 observation of the movements in a living unansesthetised annual 



by means of the Rontgen rays. In order 

 to make the shape of the stomach visible, 

 the food bread and milk is mixed with a 

 quantity of bismuth subnitrate or bismuth 

 oxychloride (Hertz). The presence of this 

 salt does not interfere with the processes of 

 digestion, but renders the gastric contents 

 opaque to the Eontgen rays. On examin- 

 ing by this means the stomach of a cat 

 which has just taken a meal, the whole of 

 the food is seen to be lying in the fundus. 

 It is marked off by a strong constriction, 

 the ' transverse band,' from the pyloric 

 portion. In about twenty to thirty minutes 

 faint waves of contraction begin a little to 

 the cardiac side of the transverse band and 

 travel slowly towards the pylorus. These 

 waves succeed one another so that the 

 pyloric part of the stomach may present 

 a series of constrictions. Their effect is to 

 force towards the pylorus the food which 

 has been digested by the gastric juice and. 

 detached from the surface of the mass in 

 FIG. 335^shaclow sketches the fundus. The pylorus remaining closed, 

 of the outlines of the the food cannot escape, and therefore is 



stomach of a cat, imme- i i i x i a 



diately after a meal (il.O), squeezed back, forming an axial reflux stream 

 at various intervals after- towards the cardiac end. These contractions 



wards(12.0, 2.0, 3.30,4.30). , ,, , , -, 



^situation of cesophageal last throughout the whole period of gastric 

 opening ; yz, ' transverse digestion, and become more marked as diges- 



and*' pc por" tion proceeds. Their effect is to bring the 

 tions. (\v. B. CANNON,) whole of the food in close contact with every 

 particle of pyloric mucous membrane and to cause a thorough mixture 



of food and gastric juice, At varying periods after a meal, according 



782 



