THYROID FUNCTION IN ANIMALS

"In humans and animals, thyroid hormones play a vital role in regulating metabolic and cellular mechanisms", says Sushant Sadotra, Ph.D of Bioguard Corporation.

There are four primary functions of the thyroid gland in animals; trapping the iodide, synthesis of thyroid hormones, storage, and release of hormones.

Introduction:

Thyroid is one of the endocrine glands in vertebrates. It is a bilobed structure located below the larynx and overlays the trachea in animals. In different animals, anatomical variations of the thyroid are primarily seen in the isthmus connecting the gland's two lobes. The size of the gland is approximately 0.20% of body weight. However, the size may increase due to iodine deficiency, ingestion of goitrogenic toxins, tumors, and hyperactivity of the gland, or maybe reduced to fibrotic due to hyperthyroidism.

Thyroid follicles are the thyroid gland's functional units with a spherical structure composed of an inner core of the thyroglobulin-hormone complex, colloid. The colloid is surrounded by an outer monolayer of follicular cells and acts as the storage tank of thyroid hormone. The overall size of the follicles and the shape of their follicular cells may differ due to the functional activity of the thyroid gland. The dormant follicular cells are squamous-shaped compared to the tall columnar, highly active follicular cells. Other than colloid, the thyroid C-cells are interspersed between the follicles. The thyroid C-cells are the source of the hypocalcemic hormone calcitonin that is associated with calcium metabolism. The third type of tissue embedded in the thyroid gland is the parathyroid. The parathyroid is the source of the hypercalcemic hormone parathormone.

Functions of the Thyroid Gland: