160 Anatomy Applied to Medicine and Surgery. 



the recurrent laryngeal, which supplies all the laryngeal 

 muscles with the exception of the crico-thyroid, be dis- 

 turbed, there would result spasm of these muscles, on the 

 left side, if the nerve be only irritated, but paralysis of one 

 vocal cord the left if the nerve be forcibly compressed. 

 If both cords were paralyzed, there would be a condition 

 of almost complete aphonia present, but, where only one 

 cord is affected, as in thoracic aneurism, the other, passing 

 over towards the injured side, compensates, so that the 

 voice is altered in pitch only. When the branches of the 

 pneumo gastric to the lungs are implicated the. cough ex- 

 citing fibres and the muscular filaments may be excited, 

 when the nerve is only irritated, with the result that there 

 is increased frequency of coughing and, possibly, asth- 

 matic paroxysms. Should, however, these fibres to the 

 lungs be paralyzed, no warning could be given by them as 

 to the presence of mucus, etc., in the bronchial tubes, so 

 that secretions would collect in the lungs and cause irrita- 

 tion, and inasmuch as, the trophic filaments of the nerve 

 would be also affected, inflammatory action would likely 

 follow this irritation. Motion of the oesophagus and 

 stomach would be interfered with if the branches to these 

 organs were disturbed. 



Pressure on the sympathetic will, among other effects, 

 produce vasomotor disturbance in the parts supplied by 

 this system (page 155). These vasomotor disturbances 

 may show themselves in the shape of an anaemic condition 

 of those particular regions if the sympathetic be merely irri- 

 tated, but, if the nerve be compressed, a state of conges- 

 tion would result. Should the cilio-spinal fibres, that 

 emerge from the upper dorsal portion of the cord and pass 

 into the sympathetic system, be affected, there will be dila- 

 tation of the pupil and protrusion of the eyeball, if the 

 nerves be irritated, or, contraction of the pupil and retrac- 



