318 THE HUMAN BODY. 



apron. After middle life much fat frequently accumulates 

 in the omentum, so that it is largely responsible for the 

 "fair round belly with good capon iin'd." The protrusion 

 I to the left side of the cardiac orifice. Fig. 96, is the/ww- 

 dus or great cut de sac. The size of the stomach varies 

 greatly with the amount of food in it; just after a mode- 

 rate meal it is about ten inches long, by five wide at its 

 broadest part. 



Structure of the Stomach. This organ has four coats, 

 known successively from without in as the serous, the mus- 

 cular, the submucous, and the mucous. The serous coat is 

 formed by a reflexion of the peritoneum, a double fold of 

 which slings the stomach; after separating to envelop it the 

 two layers again unite and. hanging down beyond it, form 

 the great omentum. The muscular coat (Fig. 54*) consists of 

 unstriped muscular tissue arranged in three layers: an outer, 

 longitudinal, most developed about the curvatures; a circu- 

 lar, 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 shrunk, this coat is thrown into folds. During 

 digestion the arteries supplying the stomach become dilated 

 and, its capillaries being gorged, its mucous membrane is 

 then much redder than when the organ is empty. 



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 pneumogastric nerves 

 (p. 171) end in the stomach, and it also gets branches from 

 the sympathetic system. 



Histology of the Gastric Mucous Membrane. Exami- 

 nation of the inner surface of the stomach with a hand 



*P. 124. 



