الفهرس 
Embryology of the Thyroid GlandOnly 14 pages are availabe for public view
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Abstract
Seventy two young (N) weaned male albino rats (3 weeks old) and seventy two adult (A) male albino rats (4 months old) were used in the present study. Both young and adult rats were classified into two main groups (control and experimental); each of the experimental groups were divided into two subgroups (low and high dose-treated subgroups).The sodium fluoride was administered to the animals dissolved in water in a concentration of 10 or 30 mg/L. Two, four, six and eight weeks after the beginning of the experiment, five rats from each control group and each of the experimental subgroups were anaesthetized. Blood samples were taken from the heart of each rat for assessment of the serum concentration of T3 and T4. The thyroid glands were dissected (supported by the trachea). In each sample the trachea was divided into two halves; each had one lobe of the gland. The right lobe was used for light microscopic study (Hx & E, PAS and immunohistochemistry) and the left one was used for electron microscopic study. A quantitative morphometric study was done for the measurements of the external follicular diameter and the epithelial height obtained from Hx & E stained sections, while the area percent and density of reaction of C-cells were recorded from the immunostained sections.