STOMACH. 47 



shape, but may be more accurately considered as a 

 conoid bent upon itself. Into its left and largest portion, 

 the oesophagus enters, and this is called the cardiac 

 orifice. From the extremity of the opposite portion, we 

 see the origin of the intestinal canal ; the opening by 

 which this communicates with the stomach, is called the 

 pyloric orifice. The relation of the stomach to the 

 surrounding parts varies according as it is distended 

 with food, but it is not worth our while to notice 

 all these changes of position. Its external or peri- 

 toneal coat is reflected upon it from the walls of the 

 abdomen, but its edges, instead of uniting together 

 where they meet on the opposite side, are prolonged 

 down some distance before they unite, forming what is 

 called the omentum, or caul. Being liberally furnish- 

 ed with fat and cellular tissue, it lies down over the 

 stomach like a curtain, and gives to this organ addi- 

 tional warmth and security. The stomach is abundantly 

 supplied with nerves and blood-vessels, receiving four 

 great arteries, three of which are exclusively appropri- 

 ated to itself. So important is this organ to the living 

 economy, and so extensive and numerous are its sym- 

 pathies with all the others, that disease or derangement 

 in almost any part of the system, generally disturbs 

 sooner or later sometimes immediately the natural 

 harmony of its functoins. A single blow directly over 

 the region where it is situated, has been known to pro- 

 duce death with the rapidity of lightning. 



Emily. Now, I hope you are ready to relate the 

 changes which the food undergoes in this wonderful or- 

 gan. Pray, what prevents it, if the pyloric orifice re- 

 mains open, from passing directly down into the intes- 

 tinal canal ? A valve, or some other contrivance, 1 should 

 think was necessary, in order to keep it closed while the 

 food is digesting. 



Dr> B- Do not be impatient ; you shall understand 

 it all in due season. But, for the present, we must let 

 the subject rest till our next conversation. 



