CHAPTER II. 

 I. PATHOLOGY OF THE PARATHYROID GLANDS. 



FUNCTIONS OF THE PARATHYROIDS 



The parathyroid glands were discovered by Sabdstroem 

 in 1880. They consist of two pairs of small glands, the 

 size of a lentil, situated on either side of the thyroid. 

 There are two superior parathyroids corresponding to the 

 union of the upper and lower two thirds of each lobe of 

 the thyroid (sometimes they are included in the thyroid 

 itself) and two inferior parathyroids on the lateral sur- 

 face of the gland, in the neighborhood of the inferior 

 thyroid artery. 



It has the structure of a gland of internal secretion 

 although different from the thyroid. It consists of rows 

 of glandular cells in intimate contact with the blood and 

 lymphatic capillaries. 



The product of their secretions is not yet well deter- 

 mined. All that we know is that the parathyroid cells 

 contain a colloidal substance; iodine, glycogen, and various 

 fatty substances, the exact part played by them not 

 having been yet determined. 



The parathyroid have certain peculiar physiological 

 properties brought out at first by Gley and de Moussu 

 and since then by other investigators. 



Their destruction in animals results in three types of 

 disorders: nervous, toxic and trophic. 



1. NERVOUS DISORDERS. In the cat or the dog, in 

 which all the parathyroids have been removed, certain 

 phenomena occur two to three days after the operation. 



The animal begins to shake, has muscular tremors and 

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