436 



ANATOMY OF VERTEBRATES. 



ib. p. This membrane is usually of a pale pink colour, deeper 

 tinted at the pyloric than at the cardiac portion, and produced 



334 



into numerous wrinkled folds or 



rugae. 



which 



Longitudinal section of the 

 pylorus. CXLVJH". 



are not so soon effaced, under distension, as in 

 the quadrumanous stomach. The ' basal ' part 

 of the membrane is areolar or cellular tissue, 

 connecting it to the muscular coat ; it also 

 supports the vessels and nerves, forms the 

 cylinders of the gastric tubules, and is covered 

 by a delicate epithelial layer of the columnar 

 kind. The gastric tubules, fig. 337, are cylin- 

 ders of the basal membrane, packed vertically 

 side by side, and filled by cells : their inserted 

 end, d, is closed : they expand slightly before reaching the free 

 surface of the membrane, where their margins become continuous 

 with each other, so as to form a series of low ridges, the height and 

 width of which vary somewhat in different parts of the stomach. 

 The length of these tubes is about T , ; V^ U f an inch at the middle of 

 the organ, almost double that length at the pyloric portion, and 

 half that length at the cardiac region, a difference causing the 

 different thickness of the mucous membrane in these parts of the 

 cavity. Their diameter is about ^^th of an inch, and is a little 

 increased in the pyloric ones : in some of these, blind processes are 

 continued from the inserted end ; as commonly seen in the Dog, 

 fig. 349. Toward the outlet the tubule is occupied by ( columnar 



epithelial cells,' fig. 337, c : 

 the deeper portion is filled by 

 oval nucleate cells, attaining 



in some cases T ^Vo* n f an 

 inch in diameter, ib. b. The 

 tubules are connected together 

 by a finely fibrous form of 

 areolar tissue, in which their 

 blind ends, or branches, are 

 imbedded. 



The principal arteries of the 

 stomach, derived from the ( crc- 

 liac axis,' are the l arteria coro- 

 naria ventriculi,' fig. 335, , 

 which courses along the lesser curvature ; the ' gastro-duodenalis,' d, 

 which gives off the ' arteria pylorica,' g ; the ( gastro-epiploica,' 

 ' dextra,' e, and ( sinistra,' i. The branches of all these arteries 

 have a tortuous course and freely inosculate ; their ramuli per- 



335 



Arteries of the stomach, as seen by raising it 



CXLVIII''. 



