THE BACK. 419 



the expression of anguish on the patient's face when the middle ear is the seat of 

 p. tin ; an expression determined by the auricular communicating branch of the 

 ninth nerve with the seventh or facial nerve, and also with the pneumogastric 

 nerve, as represented in figure 293. 



3. With the hypoglossiil nerve, by which the movements of the tongue arc 

 h.irmoni/.ed with both deglutition and vocal action. 



4. Witli the sympatkttu nerre, by which the action of the heart and lungs 

 ma>' be brought into harmony with their environment. 



The physiological communications of the vagus nerve are : 



1 . With the spinal accessor)' nerve. 



2. With the glosso-pharyngcal nerve. 



3. With the hypoglossal nerve. 



4. With the sympathetic nerve. 



5. With the first and second cervicals. 



6. With the facial or seventh cranial nerve. 



This communication is for the purpose of harmonizing respiration and the 

 ingestion of food, in their broadest terms, in consonance with a conservative and 

 ii-sthetic adjustment of inner to outer relations. 



Xtiii/e (lie brandies of tlic ragns nerve. 



1 . A recurrent branch to the dura mater. 



2. The auricular branch, given off from the ganglion of the root, is joined by 

 a branch of the petrous ganglion of the glosso-pharyngeal. (Fig. 293.) This 

 branch divides into two : one communicates with the posterior auricular branch 

 of the facial, the other joins the facial nerve in its canal. The auricular branch 

 of the tenth cranial nerve is called Arnold's nerve. 



3. The pharyngeal is the prime motor nerve of the pharynx. It unites with 

 the glosso-pharyngeal, superior laryngeal, and sympathetic branches to form the 

 pharyngeal plexus. The principal fibres of the pharyngeal branch of the pneumo- 

 gastric are derived from the accessory part of the spinal accessory nerve. 



4. The superior laryngeal nerve is the nerve of sensation to the mucous mem- 

 brane of the larynx, and of motion to the crico-thyroid muscle. 



5. The inferior laryngeal nerve is the motor nerve to all the intrinsic muscles 

 of the larynx except the crico-thyroid. This is also called the recurrent laryn- 

 geal. 



6. The cervical cardiac branches communicate with the sympathetic, and pass 

 to the superficial and deep cardiac plexuses. 



7. The thoracic cardiac branch has a double origin : (i) From the trunk of 

 the vagus ; (2) from the recurrent laryngeal nerve. They are distributed to the 

 cardiac plexus. 



8. The anterior pulmonary branches unite with the sympathetic to form the 

 anterior pulmonary plexus, which is found on the front of the root of the lung. 



9. The posterior pulmonary branches unite with sympathetic nerves to form 

 the posterior pulmonary plexus. This is larger than the preceding, and found on 

 the posterior part of the root of the lung. (Fig. 151.) 



10. The cesophageal plexus supplies the oesophagus and pericardium. It is 

 formed by the union of branches from both the right and left pneumogastric 

 nerves. The plexus is also called the plexus gulje, because gula means gullet. 



1 1. The terminal branches are the gastric. The branches from the left vagus 

 supply the anterior, those from the right the posterior, surface of the stomach. 

 They unite with the sympathetics and assist also in forming the splenic and 

 hepatic plexuses. 



/V.\rr/<V tlie sfindl MVV.OWT neri-e. 



This is the eleventh cranial nerve. It leaves the cranium by the jugular 

 foramen with the ninth and tenth nerves and the internal jugular vein. It has : 



