THE GASTRIC FLUID. 



are also small closed sacs beneath tlie surface of the 

 mucous membrane, resembling exactly the solitary glands 

 of the intestine, to be described hereafter. Their num- 

 ber is very variable, and they are found chiefly along 

 the lesser curvature of the stomach, and in the pyloric 

 region, but they may be present in any part of the organ. 

 According to Dr. Brinton they are rarely absent in children. 

 Their function probably resembles that of the intestinal 

 solitary glands, but nothing is certainly known regarding it. 



The blood-vessels of the stomach, which first break up 

 in the submucous tissue, send branches upward between 

 the closely packed glandular tubes, anastomosing around 

 them by means of a fine capillary network with oblong 

 meshes. Continuous with this deeper plexus, or prolonged 

 upwards from it, so to speak, is a more superficial network 

 of larger capillaries, which branch densely around the 

 orifices of the tubes, and form the framework on which are 

 moulded the small elevated ridges of mucous membrane 

 bounding the minute, polygonal pits before referred to. 

 From this superficial network the veins chiefly take their 

 origin. Thence passing down between the tubes, with no 

 very free connection with the deeper inter-tubular capillary 

 plexus, they open finally into the venous network in the 

 submucous tissue. 



The nerves of the stomach are derived from the pneumo- 

 gastric and sympathetic. 



Secretion and Properties of the Gastric Fluid. 



While the stomach contains no food, and is inactive, no 

 gastric fluid is secreted ; and mucus, which is either 

 neutral or slightly alkaline, covers its surface. But imme- 

 diately on the introduction of food or other foreign sub- 

 stance into the stomach, the mucous membrane, previously 

 quite pale, becomes slightly turgid and reddened with the 

 influx of a larger quantity of blood ; the gastric glands 

 commence secreting actively, and an acid fluid is poured 



