DIGESTION 131 



29. Movements of the Stomach. The inner coating of the 

 stomach is the mucous membrane, which, as we have seen, 

 furnishes the gastric juice. Next to this coating lies another, 

 called the muscular coat, composed of involuntary muscular 

 fibres, some of which run circularly, and others in a longitudinal 

 direction. These expand to accommodate the food as it is intro- 

 duced, and contract as it passes out. In addition, these fibres 

 are in continual motion while food remains in the stomach, 

 and they act in such manner that the contents are gently 

 turned round from side to side, or from one end of it to the 

 other. 



30. By these incessant movements of the stomach, called 

 the peristaltic movements, the gastric juice comes in contact 

 with all parts of the food. We are, however, not conscious 

 that these movements take place, nor have we the power to 

 control them. When such portions of the food as are suffi- 

 ciently digested approach the pylorus, it expands to allow them 

 to pass out, and it closes again to confine the residue for further 

 preparation. 



31 . The knowledge of these and other interesting and instruc- 

 tive facts has been obtained by actual observation ; ' the work- 

 ings of the stomach of a living human being have been laid 

 open to view and examined the result of a remarkable acci- 

 dent. Alexis St. Martin, a Canadian voyageur, received a gun- 

 shot wound which laid open his stomach, and which, in healing, 

 left a permanent orifice nearly an inch in diameter. Through 

 this opening the observer could watch the progress of digestion, 

 and experiment with different articles of food. Since that 

 occurrence, artificial openings into the stomach of the inferior 

 animals have been repeatedly made, so that the facts of stomach- 

 digestion are very well ascertained and verified. (Bead Note 4. ) 



4. The Digestibility of Solid Foods. "The accompanying table 

 shows some of the results obtained from the experiments of Dr. Beaumont 



29. Muscular coat of the stomach ? Expansion and contraction of its fibres ? Action 

 of the fibres ? 



80. Peristaltic movements ? What is said of our consciousness of and power over these 

 movements ? Describe the movement of the pylorus. 



31. How has the knowledge and the workings of the stomach been ascertained ? St. 

 Martin ? How else ? ^..j L fr ^ ^ 



Of T H f 



