236 INTERNAL SECRETION 



wasting lead to death in a few days. If but one para- 

 thyroid is left behind this condition does not occur. 



It has been observed among Himalayan children that 

 in certain cretins nervous manifestations are prominent. 

 In these the parathyroids have been found to be specially 

 involved. 



Recently considerable evidence has accumulated to show 

 that parathyroid deficiency is associated with disturbance 

 of guanidine ^ metaboUsm. The evidence is as follows : — 



1. Guanidine is formed in the intestine by bacterial 

 putrefaction. 



2. During intestinal putrefaction, symptoms resembhng 

 tetania parathyropriva make their appearance. In this 

 condition the guanidine content of the blood and urine is 

 increased. 



3. Guanidine increases in the blood after removal of 

 the parathyroids. 



4. Tetany can be induced by injection of guanidine. 



As regards the effect of administration of parathyroid 

 extracts we have no reliable information. 



The evidence above detailed seems to show that thyroid 

 and parathyroids subserve functions which are entirely 

 distinct. The thyroid, while not essential to hfe, is neces- 

 sary for the proper speeding up of all the bodily functions. 

 To quote McCarrison, " the thyroid gland is to the human 

 body what the draught is to the fire." The parathyroids 

 elaborate a substance which neutrahses a toxin, probably 

 guanidine, which acts upon the neuromuscular system. 



THE SUPRARENAL GLANDS 



Structure 



Each suprarenal gland consists of two parts, the cortex 

 and the medulla. The cortex is composed of epithehal- 



^ See page 177. 



