Part of “CHAPTER 29 – MORPHOLOGY OF THE THYROID GLAND“

The normal adult thyroid gland consists of two lobes connected by an isthmus. Thyroid tissue is light brown, and the cut surface often glistens. The normal gland is surrounded by a delicate fibrous capsule and weighs 15 to 25 g. The normal thyroid is attached loosely to neighboring structures, and the fascial planes are distinct. Nodules, which are common in the adult gland, can be seen grossly in ˜10% of the population in the United States.17

The vascular supply to the thyroid is derived from the superior and inferior thyroidal arteries; venous blood drains through thyroidal veins into the external jugular vein. The thyroid contains a rich lymphatic network; intraglandular and subcapsular lymphatics drain into the internal jugular lymph nodes.18