3o6 



THE STOMACH. 



•250. 



ramif j'in.g between the several coats and supplying them with blood (especially 

 giving off numerous capillaries to the muscular coat) and after dividing into very 

 small vessels in the submucous areolar tunic, the ultimate arterial branches (fig, 

 250, a) enter the mucous membrane, and ramifying freely, pass to its surface 



between the tubuli ; here they form a plexus (rP) 

 of fine capillaries upon the walls of the tubules r 

 and from this plexus larger vessels pass into a 

 coarser capillary network around the mouths of 

 the glands and upon the hexagonal borders of the 

 alveoli. The n-in-f. fewer in number than the 

 arteries, arise from the latter network, and take an 

 almost straight course (c, c) through the mucous 

 membrane l^etween the glands. After piercing 

 the muscularis mucosae and forming a wide venous 

 plexus in the submucous tissue, they return the 

 residual blood into the splenic and superior mes- 

 enteric veins, and also directly into the vena 

 portiB. By the Ijreakmg up of the arteries into 

 capillaries on the walls of tlie glands, these arc 

 furnished with pure blood for tlie elaljoration of 

 their secretion ; while it is the blood from which 

 that secretion has been di'awni which passes on 

 to the capillaries of the free surface, and has 

 added to it whatever materials may be taken 

 into the circulation from the contents of the 

 stomach. 



The li/mph(ttirg are very numerous. As showi: 

 by Loven,* they arise in the mucous membrane 

 (fig. 2.51) by a dense network of vessels, situate 

 between and amongst the gland-tubuli, which, 

 as well as the blood-vessels, in many jmrts they 

 enclose in sinus-like dilatations. Near the sur- 

 face of the membrane they form loops or possess 

 dilated extremities ; in all cases they appear to 

 be less superficial than the blood-capillaries. 

 At the deeper part of the mucous membrane 

 they pass into a plexus of fine vessels {h), 

 immediately underlying the tubular glands ; 

 piercing then the muscularis mucosa3 (^r), they 

 foi-m a coarser deeply-situated network (r) in the 

 submucous coat ; the vessels proceeding from 

 this network pierce the muscular coats, then follow the direction of the blood- 

 vessels beneath the peritoneal investment, and traverse lymphatic glands found 

 along the two curvatures of the stomach. 



The nerves, which are large, consist of the terminal branches of the two 

 pneumo-gastric nerves, belonging to the cerebro-spinal system, and of oficsets from 

 the sympathetic system, derived from the solar plexus. The left pneumo-gastric 

 nerve descends on the front, and the right upon the back of the stomach. 

 Xumerous small ganglia have been found by Remak and others on both the 

 pneumo-gastric and sympathetic twigs. The neiwes form gangliated plexuses 

 both between the layers of the muscular coat and in the submucous coat. 

 Their ultimate ending has not been traced. 



The pylorus. — While there is no special apparatus at the cardiac 

 orifice of the stomach for closin<^ the passage from the oesophagus, the 

 opening at the jDjloric end, leading from the stomach into the 

 duodenum, is provided with a sphincter muscle. On looking into the 



Fig. 250. — Plan of Bloop- 

 vKSSELs OF Stomach (from 

 Brinton). 



(f, small arteries passing up 

 fi'om submiicosa to break iip into 

 the fine capillary network, d, be- 

 tween tlie glands ; h, coarser 

 capillary network around the 

 mouths of the glands ; c, c, veins 

 jjassing vertically downwards from 

 the superficial network to join 

 into larger trunks ; e, in the sub- 

 mucosa. (The arteries in the 

 submucous coat do not anastomoi;e 

 so freely as here represented. ) 



* Om lymfviigarna i magsackens slemhinna. Nor J. Med. Arkiv, 1873. See also H 

 "Watney, in Centr. f. d. Med. Wiss. 48, 1874. 



