What is the thyroid?

The thyroid gland is one of the body's most important endocrine organs. Thyroid gland develops during the first twelve weeks of embryologic development. During this period, thyroid descends to its final position anterior to the trachea. Thyroid “shield gland” consists of two lateral lobes which are united by isthmus located anterior to the trachea. The pyramidal lobe represents the inferior portion of the thyroglossal duct but is not always present. The gland is covered by a thin fibrous capsule and it is posteriorly attached to the trachea and larynx. It weighs about 15-25g in adults and each lobe measure about 4-5 cm superiorly to inferiorly. The recurrent laryngeal nerves (RLN) innervate the muscles of the larynx and provide sensory innervation to a part of larynx. They ascend superiorly and medially towards the tracheoesophageal groove behind the thyroid. Identifying and protecting these nerves during surgery is crucial for their protection.  The external branch of the superior laryngeal nerve passes near the superior pole of the thyroid and innervates the larynx. It results in tensing of the vocal cords.  Injury to this nerve manifests as voice fatigue and loss of high pitch tones. 

Simply Put:  Your thyroid is a gland located at the lower part of your neck, just below your Adam’s apple. It is shaped like a butterfly – each wing, or lobe of your thyroid lies on either side of your windpipe.