Gross and Microscopic Anatomy of Thyroid Gland of One-humped

Tissue samples of thyroid glands of 16 healthy camels (Camelus dromedarius) were investigated under two age groups i.e. group A (3-5 years) and group B (6-10 years)) with equal number of animals, for their gross and microscopic anatomy. Gross studies revealed that thyroid glands were located near the first ring of trachea and had two lobes, connected by an isthmus. They were of reddish brown in colour. The values of weight, length and width of thyroid glands were 45.7 ± 0.35 and 50.65 ± 0.26 g, 36 ± 0.46 and 6.36 ± 0.33 cm, and 3.35 ± 0.29 and 3.53 ± 0.21 cm in groups A and B, respectively. The diameter of the glands averaged 0.97 ± 0.13 and 1.05 ± 0.14 cm in groups A and B, respectively. 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 follicles in variable numbers, the large and small. The large follicles were lined by low cuboidal epithelium, while the small follicles were lined by high cuboidal to columnar epithelium. The follicles had colloid material in their lumen, probably an apocrine secretion from the lining epithelial cells. The para follicular or C-cells were absent in thyroid glands of camel.