136 The Thyroid (Jlaud 



trusion being caused by dilatation of the blood-vessels in the back of 

 the orbit, and it may be that this dilatation is caused by pressure 

 upon the cervical ganglia of the sympathetic. 

 As a secondary result, ophthalmia and even 

 ulcerative corneitis may ensue. 



The goitrous tumour may press upon the 

 trachea and flatten it, causing dyspnoea and 

 dysphasia ; if only one lateral lobe be enlarged 

 the windpipe and gullet may be pushed to the 

 opposite side. Extending laterally, the tumour 

 thrusts outwards the carotid artery and the in- 

 ternal jugular vein and the vagus, disturbing 

 the cerebral circulation. The voice is altered, 

 either from pressure upon the trachea or upon 

 Bronchoc^Tgoitrewith the recurrent laryngeal nerve. A large mass 

 dilated superior thyroid of the gland across the front of the neck im- 

 pedes flexion. 



As regards operative interference, cysts may be tapped, but the 

 vascular thyroid enlargement which is associated with exophthalmos 

 had best not be interfered with. In no case should the entire gland be 

 removed, or myxcedema will be likely to supervene, unless perchance 

 an accessory thyroid should be present. 



Division of the isthmus or removal of one lateral lobe may determine 

 atrophy of the rest of the enlarged gland ; when the chief trouble 

 is the dyspnoea the former operation should be resorted Jo. When 

 relief of dyspncea is sought by tracheotomy the surgeon should satisfy 

 himself that the tube is long enough to reach below the collapsed part 

 of the trachea, which may be very low down in the root of the neck. 



The operation for removal of half of the gland is effected by a 

 longitudinal incision through the skin, superficial and deep fascia, all 

 bleeding vessels being secured ; then, the less the knife is used the 

 better : the surgeon should enucleate the mass with his finger and 

 a blunt raspatory. The vessels entering are secured by double liga- 

 tures before being cut. and the greatest care must be taken not to pick 

 up or damage the recurrent laryngeal nerve whilst the inferior thyroid 

 branches are being dealt with. 



PHARYNX AND (ESOPHAGUS 



The pharynx ((f>apvy = fauces'), closed above by the base of the skull, 

 opens at the level of the cricoid cartilage (fifth cervical vertebra) into 

 the oesophagus ; this is its narrowest part, its widest being near the 

 hyoid bone. 



There are seven openings into the pharynx : the two posterior nares, 

 two Eustachian tubes, the mouth, larynx, and oesophagus. 



When a mass of food is impacted in the pharynx it may cause suf- 



