Transformation of the thyroid gland of horses in conditions of iodine insufficienсу
The thyroid gland (SHCH) has a multilateral impact on various systems and organs in the body of farm animals, including horses. Changes in the thyroid of horses are considered in the article with the development of hypofunction of the organ. In a state of hypofunction, the epithelial cells, from which the follicle walls consist, become flat with flattened cores. The size of the follicles is different, the diameter of some more than 500 microns. There is a lot of colloid in the follicles, it is dense. This is explained by the fact that with a decreased function of the thyroid gland, the colloid organism is almost not consumed by the horse and is completely deposited in the lumens of the follicles, increasing their size. In the histosections there are also follicles with a diameter of 50-70 μm. Epithelial cells of their walls are round or cubic. Often found areas of the gland with follicles tubular structure, the type of embryonic, as well as pictures of increased proliferation of thyroid epithelium. As a result of the process of proliferation there is a proliferation of thyroid - there is a so-called goiter. The sources for the growth of epithelial cells are the centers of mitotic division of cells in individual follicles. In follicles, reflecting the decreased functional activity of thyroid gland, there is abundant desquamation of thyroid cells in colloidal masses. Desquamates are located in the center of the follicles. Often, they contain single blood cells. Thus, the consistency of the follicular colloid of this organ depends on the functional state of the thyroid of horses.