Histological and Histochemical Study of thyroid gland in camel (Camelus dromedarius) in Al- Muthanna province

Abstract

The present study aims to identify the histological and histochemical features of the thyroid glands in adult male camels.  Fifteen male camels were used in the current study. A histological examination was conducted to delineate the overall body structure of the thyroid gland, including microscopic measures of capsule thickness and the diameters of several thyroid follicles.  Histological findings indicate that the thyroid glands in each animal were encased in a capsule composed of two layers of collagen fibers.  The thyroid gland comprises follicles of varying forms and sizes, namely large and small follicles, inside each lobe. The histological examination identified the parafollicular cells in the camel, commonly known as C-cells.  C-cells are large, spherical, and oval, with cytoplasm that is stained lighter than that of follicular cells.  Their nuclei exhibited extensive staining.  They originated as a singular cell or in pairs or groups.  In the tissue part, it was seen that certain C-cells had been supported by a basement membrane, which served as the foundation for both follicular and parafollicular cells.  Conversely, other cells were organized randomly inside the intermolecular tissue, isolating the C cells from the follicular wall.  The parafollicular cells, detected in tissue slices either alone or in small clusters, possess an oval or rounded morphology, a spherical nucleus, and lightly stained cytoplasm. Histochemical analysis revealed that the capsule, colloidal substance, basement membrane, and parafollicular cells of the thyroid gland had pronounced responses.  To do PAS staining All components of the thyroid glands displayed a favorable reactivity to PAS _ AB and Masson Trachoma stain. Conclusion, the camel's thyroid structure was similar to that of large ruminants. while 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.