|Statement||by Chalmers Watson....|
|The Physical Object|
|Number of Pages||387|
Due to the central role of the thyroid gland in the overall health of an animal, it is commonly included as a protocol required tissue for morphological examination in most toxicity and carcinogenicity studies. 2. Normal Thyroid Gland Embryology. The thyroid gland is the first of the endocrine tissues to develop in the rat. The functional unit of the thyroid gland is the follicle, which is composed of epithelial cells arranged as hollow vesicles of various shapes ranging in size from to mm in diameter; it is filled with a glycoprotein colloid called thyroglobulin (Figure ).There are about three million follicles in the adult human thyroid gland. Epithelial cells lining each follicle may be cuboidal or. Structure and Function of Thyroid Gland. Introduction. Thyroid Gland is a two-lobed gland that wraps around the trachea and is located at the base of the neck in vertebrate animals. The thyroid gland secretes two important hormones: thyroxine, which regulates the cell metabolism necessary for normal growth and development, and calcitonin, which stimulates the formation of bone and helps. The thyroid gland is composed of 2 lobes connected by an isthmus. It is surrounded by a dense irregular collagenous connective tissue capsule, in which (posteriorly) the parathyroid glands are embedded. The thyroid gland is subdivided by capsular septa into lobules containing follicles. These septa also serve as conduits for blood vessels.
The thyroid gland (glandula thyroidea) is an unpaired organ located in the anterior region of the neck at the level of the larynx and the upper part of the trachea. The gland consists of two parts - the right (lobus dexter) and left (lobus sinister), connected by a narrow isthmus. The thyroid gland is rather superficial. In former papers the author has shown that diet modifies the minute structure of the thyroid gland in tame rats. The following investigation was undertaken to ascertain to what extent, if any, the thyroid of wild rats is influenced by a diet which is unusual for these animals. A series of twenty young wild rats, apparently healthy, was obtained from a hotel basement. The thyroid is a highly vascular, brownish-red gland located anteriorly in the lower neck, extending from the level of the fifth cervical vertebra down to the first thoracic. The gland varies from an H to a U shape and is formed by 2 elongated lateral lobes with superior and inferior poles connected by a median isthmus, with an average height of mm, overlying the second to fourth. The knowledge of thyroid gland weight and dimension and body weight in relation to the gestational age might be helpful to judge the thyroid structure in preterm babies. Asian Journal of Medical.