| Abstract: | Thyrocalcitonin cells (C cells) were predominantly demonstrated in the ultimobranchial (UB) structures of the thyroid gland of one‐humped camels. The UB population was observed as clear cells, either singly distributed or as groups of cells between the component cellular elements lining the UB structures. They displayed various shapes: oval, pear‐like, rounded, cubical, columnar and or ellipsoid. Those populating the cell nests or solid cellular masses were almost polygonal or ovoid in shape. The cytoplasm contained well‐developed golgi complexes, several mitochondria and characteristically presented rounded or oval membrane‐bound electron dense granules of different sizes. The latter granules were irregularly distributed within the cytoplasm especially at the vascular pole. The nucleus of C cells was relatively large, indented, occupying a more or less central position in the cytoplasm. It presented various chromatin contents; the heterochromatin variety was predominantly demonstrated at the marginal zone. However, the euchromatin occupied a more central position within the nucleus. |
