Histomorphological and scanning electron microscopic studies of thyroid gland in Jamunapari goats

Gross studies revealed that thyroid glands in Jamunapari goats were located near the first ring of the trachea and had two lobes, connected by an isthmus. Histologically, thyroid gland consisted of a connective tissue capsule and trabeculae were found extending from the capsule into the substance of the gland, which divided it into lobules. Each lobule consisted of two sized (large and small) follicles in variable numbers. The large follicles were lined by low cuboidal epithelium, while the small follicles were lined by cuboidal epithelium. The para-follicular or “C” cells were present in thyroid glands of goat. In scanning electron microscopic studies the external form of the follicles was mostly spherical and oval. The size of follicles ranged between 20 and 90 μm, whereas the colloid particles were uniform and homogenous and size of particles ranged between 3.03 and 3.10 μm.