Thyroid Embryology, Anatomy, and Physiology: A Review for the Surgeon

Abstract

The thyroid gland, an obligate structure in all vertebrates, is essential for normal development and metabolism. As a response to the varying maladies of the thyroid, surgeons have devised various techniques to extirpate part or all of the gland. Recent advances include new tools such as the ultrasonic dissector (Harmonic scalpel) and the electrothermal bipolar sealing system (LigaSure) as well as the application of minimally invasive and endoscopic techniques. As surgical approaches have evolved, so has our understanding of the genetics of thyroid mor-phogenesis and the biochemistry of thyroid function. This review integrates recent work on thyroid physiology with our present knowledge of thyroid development and anatomical variations.