Gross and histological features of thyroid gland in adult male one humped camel Camelus dromedarius in AL-Muthanna province

This study aimed to focus light on the histomorphometry structure of the camels' thyroid glands. For this study, 15 adult male camels were used. Grossly: The thyroid gland was made up of two long, oval lobes near the sides of the trachea that were connected from the ventral side by an isthmus runs along the ventral edge of trachea near the level of the second and third rings. It was situated behind the larynx. The thyroid gland's right lobe was situated on the dorsomedial side of trachea, which ran from the first to the eighth rings. On the medial side of the trachea, the left lobe was situated between the second and sixth to seventh rings. The trachea was attached to the medial portion of the lobes. They have convex lateral surfaces. Additionally, the lobes' ventral and dorsal borders were convex. Histologically; The thyroid gland was divided into different lobules by the penetration of the trabeculae from the collagenous connective tissue capsule that encloses it. Follicles were create the lobules, which differ in size and shape. Large follicles were dormant and found in the gland's periphery, whilst small follicles were active and found in the gland's center. The follicles came in a variety of forms and sizes, including oval, irregular, circular, and polygonal. The vascular bed of the gland's central regions is larger than that of its outer regions. According to this study, the thyroid gland of camels contains parafollicular cells, the majority of which are found in the gland's center. These cells are far less numerous than the follicular cells and were more frequently found in the spaces between the gland's tiny follicles. Colloid was abundant inside the follicles, and these cells are infrequently found in the gland's periphery. The activity of the central tiny follicles was compatible with the well-developed loose connective tissues and vascular bed in the gland's center. Conclusion, With a few exceptions, the camel's thyroid structure was similar to that of large ruminants. It had a thin capsule, only two types of follicular cells; parafollicular cells were very few, and a different type of colloid. All of these factors helped the camel adapt to hot, dry, and unfavorable climates.