CHAPTEK VIII. 



PNEUMOGASTRIC!, OK PAR VAGUM NERVE. 



Pneumogastric nerve (second division of the eighth) Physiological anatomy 

 Properties and functions of the pneumogastric General properties of the 

 roots Properties and functions of the auricular nerves Properties and 

 functions of the pharyngeal nerves Properties and functions of the supe- 

 rior laryngeal nerves Properties and functions of the inferior, or recurrent 

 laryngeal nerves Properties and functions of the cardiac nerves, and influ- 

 ence of the pneumogastrics upon the circulation Depressor-nerve of the 

 circulation Properties and functions of the pulmonary branches, and influ- 

 ence of the pneumogastrics upon respiration Properties and functions of 

 the oesophageal nerves Properties and functions of the abdominal branches 

 Influence of the pneumogastrics upon the liver Influence of the pneumo- 

 gastrics upon the stomach and intestines Summary of the distribution, 

 properties, and functions, of the pneumogastrics. 



OF all the nerves emerging from the cranial cavity, the 

 pneumogastric, the second division of the eighth pair, pre- 

 sents the greatest number of anastomoses, the most remark- 

 able course, and the most varied and interesting functions. 

 Arising from the medulla oblongata by a purely sensory 

 root, it communicates with at least five motor nerves in its 

 course, and is distributed largely to muscular tissue, both of 

 the voluntary and the involuntary variety. Finally, there 

 is no nerve that has been the subject of such extended and 

 elaborate anatomical and physiological investigations, and 

 none, concerning the properties and exact functions of which 

 there has been so much difference of opinion. 



TTe shall have to treat of the influence of the pneumo- 

 gastric upon the act of deglutition, the heart and circulatory 



