308 CLINICAL APPLIED ANATOMY. 



Intrinsic cancer, on the other hand, is of slow growth, and 

 glandular infection is rare. The growth tends to spread round 

 to the opposite side or to the subglottic region rather than 

 upwards. 



The connexion between the lymphatics of the epiglottis and 

 the base of the tongue affords an explanation of the tendency of 

 cancer of the epiglottis to infect the tongue base. 



The lymph glands beneath the sterno-mastoid muscle are those 

 which finally receive the lymphatic of the larynx. These glands 

 communicate below with the supra-clavicular, but not with the 

 mediastinal groups. The efferent lymphatics of the supraglottic 

 area reach the glands by perforation of the lateral part of the 

 thyro-hyoid membrane. Of the subglottic lymphatic trunks, 

 some pierce the thyro-hyoid membrane and others emerge 

 between the cricoid cartilage and the trachea. On their way to 

 the lower glands beneath the sterno-mastoid, the subglottic 

 lymphatics may traverse small glands on the front of the 

 larynx and trachea and along the course of the recurrent 

 laryngeal nerves. 



Of the clinical symptoms, hoarseness is easily explained by 

 involvement of the vocal cords. Dysphagia is naturally most 

 marked when the epiglottis or posterior part of the cricoid 

 cartilage is invaded. The radiation of pain to the neck and ear 

 is due to reflection along the superior laryngeal nerve to the 

 auricular branch of the vagus. Laryngeal paralysis is of 

 complex origin, but in some instances may be due to involvement 

 of the motor filaments of the recurrent laryngeal nerve. 

 Laryngeal anaesthesia is due to the implication of the sensory 

 branches of the laryngeal nerves. 



THE BEONCHI AND LJJNGS. 

 BRONCHIECTASIS. 



The bronchi which have a descending course are more likely 

 to become dilated than those which pass upwards, since 



