MYXCEDEMA. 293 



of the thyroid gland. In those cases where the gland is enlarged, 

 its function is assumed to be in abeyance. It is not easy to form 

 a definite opinion as to the presence of thyroid atrophy by an 

 examination of the neck. The isthmus of the gland usually 

 crosses the second, third, and perhaps the fourth, rings of the 

 trachea. If these rings can be distinctly felt atrophy may be 

 assumed, but in some persons the isthmus is congenitally absent, 

 and in others, owing to its thick coverings, the trachea cannot be 

 satisfactorily palpated. The lateral lobes, as a rule cannot be 

 felt at all. 



The general increase of bulk of the body in myxoedema is due 

 to changes in the skin and subcutaneous tissues. Where the 

 subcutaneous connective tissue is lax and abundant, the swellings 

 are most apparent. Hence swelling may be found in the eyelids, 

 face, submandibular region, the lower parts of the posterior 

 triangles of the neck, and the backs of the hands and feet. 

 Where the skin is firmly bound to the subjacent fascia! 

 structures, as in the palms, soles and scalp, the swelling is 

 insignificant. 



The swelling of the tissues of the limbs, by destroying the 

 elasticity of the skin around the joints, interferes with the flexion 

 movements of the elbows, wrists, fingers, and thighs. The finer 

 movements of the hand suffer in particular. The mucous mem- 

 branes as well as the skin are affected. The lips become stiff, 

 swollen and everted, the buccal mucous membrane projects 

 between the upper and lower teeth and is indented. The gums 

 are swollen, and the lax tissues of the soft palate become infil- 

 trated and interfere with the movements of deglutition and articu- 

 lation. The tissues of the vulva and vagina may be similarly 

 affected. 



The epidermal appendages naturally suffer with the skin. The 

 hair follicles, the sweat and sebaceous glands become infiltrated 

 and destroyed. The nails may be cracked and furrowed, and 

 the teeth fail out. It is possible that the peripheral sense organs 

 are also involved. 



The supraclavicular swellings of cretinism are by no means 



