404 



PHYSIOLOGY. 



young animals than in adults. The removal of the gland in aged 

 carnivora is followed by the usual cachexia. 



CACHEXIA STEUMIPRIVA has been found by all observers to occur 

 with greater frequency when thyroidectomy has been performed on 

 young individuals. 



The classification of symptoms from removal of the thyroid is 

 either (a) myxcedema, or (b) cretinism. 



When the thyroid body is diseased or removed from children so 

 that its functions are obliterated, there is produced a species of 

 idiocy called cretinism. 



A like condition in adults receives the name of myxcedema. 

 Noticeable symptoms of this disease are slowness of both body and 

 mind. There is also a peculiar condition of the skin wherein there is 



Fig. 146a. Arrest of Development in a Sheep after a Thyroidectomy 

 Done Six Days? after Birth; the Larger One is the Skeleton of a Normal 

 Sheep of the same Ag?. (VoN EISELSBERG.) 



overgrowth of the subcutaneous tissue. In time this becomes replaced 

 by fat. Myxoedema was believed to be an cedematous condition 

 characterized by the presence of a large amount of mucin. That there 

 is an excess of mucin has been determined, but it is not in proportion 

 to produce this pathological condition. The disease is rather a 

 hyperplasia of the connective tissue. The integument especially swells 

 and the eyelids become puffy. At the same time the surface becomes 

 dry and there is a tendency to shed hairs and superficial epithelium 

 The hyperplastic change is followed by atropic changes, accompanied 

 at first by slight fever ; later the temperature becomes subnormal. 



In myxcedema the metabolism of nitrogenized substances is 

 lowered; there is a diminution of urea and the total nitrogen of the 

 urine. There is also a diminution of phosphoric acid, and the quantity 

 of carbonic acid exhaled. This lowered metabolism lowers the 

 temperature. In myxcedema there is a want of development in the 

 cartilages of the epiphyses, an atrophy of the genital organs, ovaries and 



