362 



THE DIGESTIVE SYSTEM 



The Lymphatics. The lymphatics arise by vascular loops or dilated 

 extremities between the secreting glands of the nmcosa. At the outer 

 border of the mucous membrane they form a delicate anastomosing 

 plexus from which branches penetrate the muscularis mucosre and 

 enter a broad submucous plexus whose efferent vessels pierce the mus- 

 cular coat on their way to lymph 

 nodes which are situated in the 

 folds of the omentum at either 

 curvature 'of the stomach. 



The Nerves. The nerves of 

 the stomach are derived from sym- 

 pathetic trunks, the splanchnic 

 nerves, and from the vagi. The 

 vagi are believed to be chiefly ex- 

 citatory, the splanchnics inhibitory 

 in function. The nerves enter 

 with the blood-vessels and pierce 

 the muscular coat. They connect 

 with two plexuses of anastomosing 

 nerve trunks: the myenteric 

 Auerbach's), in the intramuscular 

 fibrous septum, which contains 

 ganglionic enlargements at many 

 of its intersections and distributes 



FIG. 



338. TERMINATION OF SYMPA- 

 THETIC NERVE FIBERS. 



A, on smooth muscle cell; B, on cells 

 of the digestive epithelium, ileum of cat; 

 C, on cells of the digestive epithelium, 

 stomach of cat; D, on parietal cell, stom- 

 ach of cat. (Kuntz, Jour. Comp. Neur., 

 23, 3, 1913.) 



its fibrils to the smooth muscle; 

 the submucous (Meissner's), lying 

 in the deeper part of the submucosa, 

 which also contains small ganglia 



at the intersections of its anastomosing branches. This latter plexus is 

 much finer and contains smaller neurons than that of the muscular coat. 

 Pericellular capsules are apparently lacking in these plexuses (Miiller, 

 Kuntz). The submucous plexus distributes its fibrils to the mucosa, 

 where they terminate in and about the walls of the blood and lymphatic 

 vessels, and to the epithelium of the secreting glands, where they end 

 as varicose fibrils upon the cells. Kuntz (Jour. Comp. Neur., 23, 3, 

 1913) suggests- that the ganglia of the myenteric and submucous plexus 

 include both motor and sensory neurons, and that the fibers which 

 terminate on cells of the digestive epithelium are the dendrons of sen- 

 sory cells. 



