Morphofunctional changes in the thyroid gland and pituitary tyrotropes in rams of the Russian long-haired breed in different seasons of the year

Abstract

In mature rams, the signs of high functional activity of the thyroid gland are observed in the autumn period. An increase in the diameter of the thyroid follicles (109.1±0.58 microns) is marked, the height of the epithelium (9.6±0.11 microns) and the area of the thyrocyte nuclei (32.8±0.38 μm2) increase statistically significant (P<0.001). In the pituitary gland of rams in the autumn period, there is an increase in the number of tyrotropes. The cytoplasm of tyrotropes is filled with secretory granules, which reflects the high level of their functional activity.