406 THE HUMAN BODY 



tures; a circular, evenly spread over the whole organ, except 

 around the pyloric orifice where it forms a thick ring; and an inner, 

 oblique and very incomplete, radiating from the cardiac orifice. 

 The submucous coat is made up of lax areolar tissue and binds 

 loosely the mucous coat to the muscular. The mucous coat is a 

 moist pink membrane which is inelastic, and large enough to line 

 the stomach evenly when it is fully distended. Accordingly, when 

 the organ is empty and shrunken, this coat is thrown into folds, 

 which disappear when the organ is distended. During digestion 

 the arteries supplying the stomach become dilated and, its capil- 

 laries being gorged, its mucous membrane is then much redder 

 than during hunger. 



The blood-vessels of the stomach run to it between the folds of 

 peritoneum which sling it. After giving off a few branches to the 

 outer layers, most of the arteries break up into small branches in 

 the submucous coat, from which twigs proceed to supply the close 

 capillary network of the mucous membrane. 



The nerves of the stomach are chiefly derived from the vagi. 

 In the lower part of the thorax these nerves consist mainly of non- 

 medullated fibers, and lie on the sides of the gullet, across which 

 they interchange fibers by means of several branches. On entering 

 the abdomen the left vagus passes to the ventral side of the 

 stomach, in which it ends : the right supplies the dorsal side of the 

 stomach, but a considerable portion of it passes on to enter the 

 solar plexus, which lies behind the stomach and contains several 

 large ganglia. The sympathetic also supplies gastric nerves which 

 mainly go to the blood-vessels. In the muscular coat of the stom- 

 ach are many nerve-cells. 



Histology of the Gastric Mucous Membrane. Examination of 

 the inner surface of the stomach with a hand lens shows it to be 

 covered, except in the fundic region, with minute shallow pits. 

 Into these open the mouths of minute tubes, the gastric glands, 

 which are closely packed side by side in the mucous membrane; 

 something like the cells of a honeycomb, except that each is open 

 at one end. Between them lie a small amount of connective tis- 

 sue, a close network of lymph-channels, and capillary blood- 

 vessels. The whole surface of the mucous membrane is lined by a 

 single layer of columnar mucus-making epithelium cells (Fig. 130). 

 These dip down and line the necks of the tubular glands. The 



