Abstract
Objective: The purpose of this study is to comprehend the structural features of the thyroid gland in chicks, identifying its cellular components, follicular organization, and vascularization. For this study, ten broiler chickens that were one day old had their thyroid glands removed. 10% neutral buffered formalin, the standard stain used in this investigation, was applied to all specimens. The study's histological features revealed that the thyroid glands parenchyma contained a large number of follicles, all of which were filled with jelly-like colloid. Simple cuboidal cells lined the follicles; these cells looked dense. The para-follicular cells (C-cells) spread interstitial space, appeared polygonal in shape, pale stain, these cells found in fewer numbers. more massive and more pale. Their nuclei were round and the cytoplasm was faintly dyed. Follicles, the primary organs and structures of the thyroid gland, made up the majority of the samples taken from chicken thyroid glands. fortunately there were significant differences in dimensions and spatial arrangement, the follicles within the glandular parenchyma of the newborn broiler chick were already well developed. There were sporadic larger follicles, but the majority had small to medium diameters. A single layer of epithelial (follicular) cells lined the follicles, which were typically spherical in shape. Conclusion, with many colloid-filled follicles, a cuboidal epithelial lining, and few parafollicular cells, the thyroid gland in one-day-old chicks is structurally well developed, demonstrating early functional readiness and active endocrine organization.