102 HUMAN PHYSIOLOGY. 



The Pulmonary branches give sensibility to the bronchial mucous mem- 

 brane, and govern the movements of respiration. Division of both pneu- 

 mogastrics in the neck diminishes the frequency of the respiratory move- 

 ments, falling as low as four to six per minute ; death usually occurs in from 

 five to eight days. Feeble galvanization of the central ends of the divided 

 nerves accelerates respiration ; powerful galvanization retards, and may 

 even arrest the respiratory movements. 



The Gastric branches give sensibility to the mucous coat, and through 

 sympathetic filaments, which join the pneumogastrics high up in the neck, 

 give motion to the muscular coat of the stomach. They influence the 

 secretion of gastric juice, aid the process of digestion and absorption from 

 the stomach. 



The Hepatic branches, probably through anastomosing sympathetic fila- 

 ments, influence the secretion of bile, and the glycogenic function of the 

 liver ; division of the pneumogastrics in the neck produces congestion of 

 the liver, diminishes the density of the bile, and arrests the glycogenic 

 function ; galvanization of the central ends exaggerates the glycogenic 

 function, and makes the animal diabetic. 



The Intestinal branches give sensibility and motion to the small intes- 

 tines, and when divided, purgatives generally fail to produce purgation. 



Function. A great sensitive nerve, which, through anastomotic fila- 

 ments from motor sources, influences deglutition, the action of the heart, 

 the circulatory and respiratory systems, voice, the secretions of the stomach, 

 intestines, and various glandular organs. 



nth Pair. Spinal Accessory. 

 Apparent Origin. By two sets of filaments : 



1. A bulbar or medullary set, four or five in number, from the lateral or 

 motor tract of the lower half of the medulla oblongata, below the origin of 

 the pneumogastric. 



2. A spinal set, from six to eight in number, from the lateral portion of the 

 spinal cord, between the anterior and posterior roots of the upper four or 

 five cervical nerves. 



Deep Origin. The medullary portion arises in a nucleus in the lower 

 half of the floor of the 4th ventricle, common to the pneumogastric and 

 glosso-pharyngeal nerves. The spinal portion has its origin in an elon- 

 gated nucleus lying along the external surface of the anterior cornua of 

 the spinal cord, extending down to the 5th cervical vertebra. 



Distribution. From this origin the fibres unite to form a main trunk, 



