10 



PHYSIOLOGY 



CHAP. 



The epithelial cells which form the specific substance of the 

 parathyroids are columnar or polyhedral in shape; they have a 



C 



FIG. 4. Human thyroid and -parathyroid glands. A, from behind; B and C, from in front. 

 A 1, Superiorjparathyroids ; A 2, inferior parathyroids : B 1 and C 1, inferior parathyroids. 



small roundish nucleus which may exhibit karyokinesis. Accord- 

 ing to Vassale and Generali the cytoplasm of the cells is sometimes 



Fio. 5. Part of external parathyroid of last figure. (Kphn.) of 5 . Shows epithelial cells arranged 

 in columns, with intervening septa of connective tissue ; TO, HI, cells in mitotic division. 



clear or finely granular and does not stain, sometimes it has coarse 

 stainable granules. In all probability these represent two different 

 stages of functional secretory activity. 



