Vol. 7, Issue 2 (2019)
Microanatomy of the thyroid gland in sheep (Ovis aries)
Author(s): Dr. K Rajalakshmi, Geetha Ramesh, Usha Kumari, Kannan, M Siva Kumar, P Sridevi and Lakkawar AW
Abstract: A study on the Histomorphology and Histochemistry of the thyroid gland was conducted in the prenatal and postnatal age groups of sheep. For the prenatal study, the thyroid gland was collected from sheep embryos of early (42 days), mid (77.7 days) and late (128 days) gestation. Postnatal study included the collection of thyroid gland from young (<1 year), adult (1-5 years) and old (> 5 years) sheep, irrespective of the sexes. Tissue pieces were collected in different fixatives for routine paraffin embedding. Paraffin sections were used for routine and special staining techniques. Frozen sections were used for histochemical techniques. In the early gestation sheep embryo, only the central zone of the thyroid gland showed differentiated follicles. In the mid and late gestation embryos, the entire thyroid gland was differentiated into follicles. The location of C cells and ultimo branchia follicles was similar to the postnatal age groups. In the postnatal age groups, the thyroid gland was encircled by a connective tissue capsule. From the capsule, trabeculae entered the parenchyma and divided the gland into many lobules. The thyroid follicles varied in size and shape, in the different age groups studied. The diameter of the follicles showed a tendency to increase in size and became irregular in outline with advancing age. In the interfollicular area, in addition to the connective tissue fibres, nerves and capillaries, clusters of polyhedral cells were present. The ultimo branchia follicles were located in the perivascular connective tissue in the central zone and in the periphery of the thyroid gland within the capsule. The capsule of the thyroid gland was weakly PAS positive. The follicular cells and colloid showed strong PAS positive reaction. The accumulation of lipids and the presence of acid and alkaline phosphatases was noticed in the different structures of the thyroid gland.
Pages: 404-415 | 470 Views 115 Downloads
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How to cite this article:
Dr. K Rajalakshmi, Geetha Ramesh, Usha Kumari, Kannan, M Siva Kumar, P Sridevi, Lakkawar AW. Microanatomy of the thyroid gland in sheep (Ovis aries). Int J Chem Stud 2019;7(2):404-415.
