Thyroid Gland: Anatomy and Physiology

This article starts with the description of gross and microscopic thyroid anatomy, and thyroid ontogenesis through gestation. We further analyze thyroid hormones biosynthesis through its steps, from iodide uptake by thyrocytes to secretion of T4 and T3 in circulation. We focus also on other iodinated and biologically active compounds, the thyronamines, which result from thyroidal or nonthyroidal decarboxylation of thyroid hormones. Finally, we outline thyroid hormone transport in blood and thyroid hormone actions, for which we refer to specific articles.