The Endocrine System: Thyroid and Parathyroid

In the adult, the thyroid gland is located in the central compartment of the neck on the anterolateral aspect of the cervical trachea between the carotid sheaths. Patients with thyroid disorders require attentive care, and safe, successful surgery of the thyroid is dependent on an intimate knowledge of the anatomy and physiology of the gland. This review discusses nerve branches and function; arterial and venous blood supply; lymphatic drainage; histology; physiology; and thyroid hormone synthesis, secretion, and regulation. Nerve injuries and postoperative complications are summarized, as are functions of thyroid hormones. A thorough understanding of these relationships is imperative for proper medical recommendations, surgical procedure selection, and meticulous surgical technique to avoid complications. To provide safe care of patients with thyroid disorders, treating physicians must embrace the intricate details of the anatomy and physiology of this unique gland to avoid potentially devastating complications. This review contains 5 figures, 3 tables, and 29 references. Key Words: brachial cleft, lymphatic zones, recurrent laryngeal nerve, superior laryngeal nerve, nerve injury, thyroglossal duct cysts, thyroid, thyroidectomy