Gross, histological and histomorphometric studies on the thyroid gland of one humped camel (<i>Camelus dromedarius</i>) found in the semi-arid region of North Eastern Nigeria

Abstract

Thyroid glands are endocrine glands present in all mammals and secretes thyroxin, triiodothyronine and calcitonin as its major hormones which plays important role in metabolism, regulation of energy and nutrient absorption, as well as calorigenesis and normal reproductive function. We studied the thyroid gland of one humped camel found in the Northeastern part of Nigeria. A total of 18 pairs of thyroid glands(10 female and 8 male) were randomly collected from apparently healthy camels’ slaughtered at the Maiduguri municipal abattoir and were used for the studies. Grossly, the thyroid glands of both the male and the female camel studied appeared reddish brown in colour and irregular in shape. There was a significant difference (p<0.05) between the weights and lengths of the male and female thyroid gland with the female higher than the male on both parameters. Histologically, the thyroid gland studied is covered by a thick fibrous connective tissue capsule and consists of numerous follicles of various sizes. Lining the follicles are squamous to low cuboidal cells with basally located round or spherical nucleus. The area of the nucleus of the male thyroid gland (380.06 ± 20.484μm) was slightly greater than that of the female (366.09 ± 29.45μm). For the epithelial height and follicular diameter, the female thyroid gland showed a slight increase (49.597 ± 1.459μm and 362.16 ± 21.820μm respectively) compare to the male (48.75 ± 1.414μm and 363.93 ± 21.624μm respectively). Presence of parafollicular cells and fibroblast in this gland were also noted.

Keywords: Thyroid gland, parafollicular cells, colloid, gross, histomorphometrics