THE THYROID AND PARATHYROID BODIES 



959 



(c) Hyperthyroidism. The condition of hyperthyroidism may be produced in 

 animals either by the continued feeding of thyroid substance or by the intraven- 

 ous injection of thyroid extract (rabbits). It is usually initiated by frequent at- 

 tacks of tachycardia to which are added disorders of digestion and metabolism, 

 such as diarrhea, intestinal hemorrhage, emaciation, polyuria and glycosuria. 

 A few cases are also on record of persons who have taken excessive amounts of 

 thyroid for the relief of obesity and other disorders. Thus, one person ingested 

 in the course of five weeks nearly 1000 tablets of thyroid substance of about 0.3 

 gram each and developed, in addition to the symptoms just mentioned, an extreme 

 irritability of the nervous system, psychic exultation, sleeplessness and trembling 

 of the muscles. 1 This complex of symptoms corresponds almost precisely with 

 that presented by persons suffering from Basedow's disease or, as it is now more 

 commonly called, Graves' disease. In 1840, Basedow showed that the combination 



FIG. 506. EXOPHTHALMIC GOITER. 



The patient shows a goiter of moderate size; great exophthalmos, smooth forehead, 

 and abnormal expression. (MacCallum.) 



of exophthalmos, goiter and tachycardia forms a syndrome of a not infrequent 

 clinical condition which, in general, is just the reverse of that noted in thyreopriva, 

 hypothyroidism or diminished thyroid function. The heart is very rapid and 

 often irregular; the temperature is usually a degree or two above normal; the thy- 

 roid is generally somewhat enlarged ; while the eyes, owing to the wide open condi- 

 tion of the eyelids, are very prominent and staring. To these three fundamental 

 symptoms, others have been added in the course of more recent years, the combined 

 clinical picture being that of Graves' disease. Among the secondary conditions 

 might be mentioned an increased appetite and metabolism, insomnia, restlessness, 

 intensified sensations, mental excitement accompanied by hallucinations, muscular 

 tremors, anemia and loss of weight. 



The etiological connection of Graves' disease with a hyperactivity of the 



1 The therapeutics of preparations containing the active principles of the 

 internal secretions, is discussed in Harrower's "Practical Hormone Therapy," 

 Hober, New York, 1914. 



