COMPARATIVE AND TOPOGRAPHICAL ANATOMY OF THE FOWL : LXIV. SYMPATHETIC NERVOUS SYSTEM OF THE FOWL PART3.PLEXUS CELIACUS AND PLEXUS MESENTERICUS CRANIALIS

Abstract

Tlae gross anatomy of connections and distributions of llexus celiacus and Plexusmesentericus cranialis, and their relations to the splanchnic nerves in the fowl weredescribed and illustrated in detail on the basis of studies on 26 cases of macroscopicaldissection. Discussion was made at full length on the nomenclatures appearing in litera-ture and on tltose adopting in the present paper. The results obtained are shown inTable I. l-lae following findings warrant emphasis.The thoracic sympathetic nervous system is generally represented by seven pairs of ganglia and two trunks, Rami interganglionares and Rami interganglionares accessorii.The Nn. splanchnici majores arise from tlte second to tlxe fifth tltoracic ganglia and rundownward to the turning point of tlte celiac artery derived from the abdominal aorta(Table 2). They form some small ganglia, Ganglia celiaca, there. Nerves originated fromtlaese ganglia, collectively called the Plexus celiacus, are accompanied by the celiac artery.The plexus receives some anastomosing branches, collectively called the Plexus celiacusaccessorius, from Ganglia suprarenalia cranialia and Plexus mesentericus cranialis at eachlevel of the turning point of the right glandular gastric artery and the distal point ofthe caudal splenic artery. The Plexus celiacus extends along the branches of the celiacartery to form Plexus gastrici, Plexus lienalis, Plexus hepaticus, and Plexus pancreati-coduodenalis. The N. intestinalis anastomoses with the Plexus pancreaticoduodenalisnear the opening of the pancreatic duct.The N. vagus anastomoses with the Plexus gastrici at an intermediate level betweenthe glandular and the muscular stomach. Some peripheral branches of the N. vagussupply the liver along the left hepatic artery, while they are distributed in the muscularstomach. A part of the Plexus celiacus extends to the ileum and cecum along the cranialileocecal artery.Nerves from the fifth to the seventh thoracic ganglia and from the first lumbosacralganglion form the Nn. splanchnici minores (Table 2). These, nerves gather togetheraround the adrenal and form the Ganglia suprarenalia cranialia and caudalia. There areanastomosing branches between the Nn. splanchnici majores and minores. The Plexusceliacus accessorius arises from the Ganglia suprarenalia cranialia. Some nerves originatedfrom the Ganglia suprarenalia caudalia become the Plexus aorticus around the abdominalaorta. Other nerves from these ganglia form other ganglia; that is, the Ganglia mesentericacranialia located on the lateral surface of the caudal vena cava. The Plexus mesenteric