CHAPTER XI. 



GENERAL DISEASES. 



CACHEXIA STBUMIPBIVA MYX(EDEMA. 



THE thyroid is. one of the so-called ductless glands which are believed 

 to furnish internal secretions essential to normal metabolism in the body. 



Removal or destructive lesions of this gland, both in man and the 

 lower animals, ' may be followed by serious and fatal disease character- 

 ized as Caehexitt xtntmiprim. In man the more common manifestation 

 of this disease is called MyxcedenwT It occurs most frequently in middle- 

 aged women. 



The skin of the face is apt to be swollen and waxy, giving a peculiar 

 and rather characteristic appearance to the features. The skin of the 

 body is apt to be dry and rough, and the hair may fall out. Perspira- 

 tion is, as a rule, diminished. The mental condition is dull, and loss of 

 memory and insanity may occur. Bodily movement and speech are apt 

 to be impaired. The fat tissues may be atrophic, and the subcutaneous 

 tissue has been shown in some, though not all, of the cases to contain an 

 unusual amount of mucin. In some cases the fibres of the upper layers 

 of the corium are crowded apart by fluid. 



. The most marked and constant lesion in this disease is an atrophic 

 condition of the thyroid gland. The parenchyma of the gland is more 

 or less completely replaced by fibrillar connective tissue and by new- 

 formed reticular tissue resembling the lymphatic tissue of the lymph 

 nodes. The general appearance of the atrophied thyroid gland is shown 

 in Fig. 203. 



In addition to the lesion of the thyroid there are apt to be chronic 

 endarteritis and chronic diffuse nephritis. In some cases there are an 

 accumulation of small spheroidal cells about the smaller blood-vessels in 

 various parts of the body, and also petechial haemorrhages. 



If the thyroid be completely removed in young animals there is defi- 

 cient development of the osseous system, while in man the frequent asso- 

 ciation of cretinism with goitre or other thyroid lesions indicates in 

 another way the close relationship between the thyroid and cell metab- 

 olism." The nature of the substances composing the internal secretions 

 of the thyroid is little understood, but the wonderful therapeutic effects 



1 For an extensive critical and experimental study of this subject see C'unninc/fttiiit, 

 "Experimental Thyroidism," Jour. Exp. Med., vol. iii.. p. 147, 1898, bibliography. 



4 Consult Osier, " Sporadic Cretinism in America," Trans, of the Congress of Ameri- 

 can Physicians and Surgeons, vol. iv., p. 169, 1897. 



