Comparative and topographical anatomy of the fowl. 45. Sympathetic nervous system of the fowl. (2). Nervus intestinalis

Abstract

The gross anatomy of the course auad distribution of the N. intestiuaalis in the fowlis described and illustrated in detail on the basis of 17 complete dissections. Especially.tlae origin of the N. intestinalis, its distribution to the duodenum, cecum and cloaca, itsrelation to the Plexus celiacus and mesentericus cranialis, and its anastomosis with theN. N73gUS are discussed.The N. intestinalis arises from the three Ganglia coli near the distal end of theA. mesenterica caudalis, and runs rostralward along the intestine through the mesentery.These ganglia fuse with the Plexus mesentericus caudalis. Besides, they are directlyrelated to the sympathetic chain.By the site of appearance of ganglia in the N. intestinalis, this nerve can be dividedinto three parts; that is, the Pars rectocolica, ilei and jejunalis.In the caudal part of the Pars rectocolica, some branches arise from the Gangliacolt, run caudally and form other ganglia near the bursa of Fabricius. These gangliareceive anastomosing branches from the N. pelvinus and supply small branches to thedorsal wall of cloaca and bursa of Fabricius. There are about ten spindle-shaped gangliain the oral part of the Pars rectocolica. Receiving many anastomosing branches fronnthe Plexus mesentericus cranialis and the caudalis, each ganglion gives off, in its turn, about three fine branches to the large intestine.Tlaere are no ganglia in the Pars ilei, but the N. intestinalis becomes slender andsupplies about ten fine branches to the ileum.About thirty ganglia are present in the Pars jejunalis of the N. intestinalis. Theyare smaller than those in the Pars rectocolica, and are separated from one another atnarrow intervals. They receive some anastomosing branches from the Plexus mesenteri.cus cranialis, and supply some fine branches to the small intestine.Tlae cecum receives tlte nerve supply from the Plexus mesentericus cranialis. Thereis a fine branch taking a special course from the beginning of tlae Pars ilei. This branchIIIIIS tlarouglt the mesentery between duodenum and ileum, reaching the distal end ofthe A. ileocecalis cranialis, and anastomoses with the nerve fiber of the Plexus celiacusto enter the cecum. A ganglion larger in size than that located in the Pars jejunalis isfournd at the distal end of the duodenum. It receives many branches from the Plexusmeserttericus cranialis, and sends nerve fibers to the duodenal loop. Receiving still morebranches from this plexus, the N. intestinalis enters the duodenal loop up to the open-ings of the bite and pancreatic ducts.Since Marage regarded the N. intestinalis as a continuation of the N. vagus, hisdescription has been cited by many authors in their books. His, Szantroch and Hamilton, ltowever, have found out no direct anastomosis between these nerves. The author isnot able to find out such anastomosis either in the fowl. The nomenclatures of theN. intestinalis given in literature on the birds are discussed at full length. The resultsof comparison of nomenclature are shown in Tables l and 2.