THYROID AND PARATHYROIDS 



235 



Administration of Thyroid Extract 



In the normal individual this causes slight lowering of 

 blood-pressure, tachycardia, restlessness, flushing of the 

 skin, sweating, increased nitrogen excretion and diminution 

 of body fat. Sugar tolerance is decreased. 



In the cretinous or myxoedematous individual it causes 

 a rapid cure of the physical and mental condition. 



Fig. 33. — Parathyroid of cat (8chafer, The Endocrine Organs). 



Parathyroid Deficiency 



Removal of all the parathyroids with the thyroid usually 

 causes the condition known as tetania parathyropriva. 

 The muscular system undergoes fibrillar twitchings which 

 develop into well-marked clonic contractions, and cul- 

 minate in convulsive seizures. Vomiting, diarrhoea and 



