1 88 GASTRIC DIGESTION 



thickened band of fibres next the line of division is known as the 

 sphincter antri pylori (Hofmeister and Schiitz). 



The bloodvessels of the muscular coat are quite abundant and are 

 arranged in the peculiar rectangular network which they always pre- 

 sent in the non-striated muscular tissue. The nerves come from the 

 pneumogastrics and the sympathetic system and are demonstrated with 

 difficulty. 



Mucous Coat. The mucous membrane of the stomach is soft and 

 velvety in appearance and of a reddish gray color. It is loosely at- 

 tached to the submucous muscular tissue and is thrown into wide longi- 

 tudinal folds, which become effaced as the organ is distended. If the 

 mucous membrane is stretched or if the stomach is everted and dis- 

 tended and the mucus gently re- 

 moved under a stream of water, the 

 membrane will be found marked 

 with polygonal pits, or depressions, 

 enclosed by ridges, which, in some 

 parts of the organ, are quite regular. 

 These are best seen with the aid of 

 a simple lens, as many of them are 

 quite small. The diameter of the 

 pits is variable, but the average is 

 about 2iy^ f an mcn (- I2 5 niilli- 

 1 meter). This appearance is not 



Fie. ^8. Pits in the mucous membrane of >. ,. j ,, i ,1 



the stomach and openings of the glands, x 20 distinct toward the pylorus J the 



(Sappey). membrane here presenting irregular 



i, i, i, 2, 2, 2, 3, pits of different sizes; 4,5, ori- CO nical projections and well-marked 



fices of the gastric glands. . 



villi resembling those found in the 



small intestine. The surface of the mucous membrane is covered with 

 columnar or prismoidal epithelium, the cells being regular in shape, 

 each with a clear nucleus and a distinct nucleolus. 



The thickness of the mucous membrane of the stomach varies in 

 different parts. Usually it is thinnest near the oesophagus and thickest 

 near the pylorus. Its thinnest portion measures y 1 ^ to -$ of an inch 

 (0.34 to 0.5 millimeter); its thickest portion, -^g to ^ of an inch (1.6 to 

 2.1 millimeters), and the intermediate portion, about ^g of an inch 

 (i millimeter). 



Glands of the Stomach. Extending from the bottoms of the pits 

 in the mucous membrane of the stomach to the submucous connective 

 tissue, are large numbers of glands. These are arranged often in dis- 

 tinct groups, surrounded with fibrous tissue, each group belonging to 

 one of the polygonal depressions. The tissue which connects the tubes 



