Function of the thyroid gland
Anatomical illustration of the thyroid gland in its active and inactive state. In the middle: Position of the thyroid gland, under the thyroid cartilage. On the right: Inactive state, characterized by flattened cells of the follicular epithelium and little luminal colloid. On the left: active state, tall cells (productive increase of cells) and accumulation of colloid (storage form of the thyroid hormones T3 and T4).