Effects of Removal or Atrophy of Thyroid 



31 



mother's thyroid to the child ; before birth through the placenta, after 

 birth through the milk. When the atrophy is congenital it usually takes 

 the form of complete lack of development of the thyroid proper the para- 

 thyroids are generally present and well developed the condition of 

 cretinism and all the above symptoms being well marked. 



If in the adult subject either thyroid atrophy occurs or such degenera- 

 tive changes take place in the gland as materially affect its functions, the 

 condition known as myxoedema (or myxcedema adultorum to distinguish 

 it from the corresponding affection of the child) becomes manifested 

 (fig. 20). This condition, which is much more common in females than in 

 males, was described by Gull in 1873, and recognised by him to be a 







A B 



FIG. 20. Myxcedema of adult (A) before and (B) after treatment with thyroid. (Andersson.) 



cretinoid condition of adult life; and subsequently, in 1877, by Ord, who 

 gave the name to the disease and showed that it is associated with 

 changes in the thyroid. It is characterised by thickening and swelling of 

 the integument, which pits on pressure, the pitting disappearing on relax- 

 ing the pressure ; by the skin becoming dry and the hairs falling out ; by 

 a low body temperature ; and by mental dullness and general impairment 

 of sensibility. In cases of myxcedema in the human subject, Brun and Mott 

 have found general chromatolysis of nerve-cells of subacute character. 

 Both in spontaneous and in operative myxcedema the metabolic processes 

 are diminished in activity, so that although less food is taken the body 

 weight may increase. Regenerative changes also occur more slowly. 

 There is usually a considerable deposition of fat, especially under the skin. 

 The activity of the sexual functions is diminished in both sexes. There is 

 a diminution in the amount of oxygen consumed and in the amount of 

 nitrogen excreted. There is increased tolerance for sugar, so that a con- 



