Angioarchitecture of the canine thyroid gland.

The extrinsic vasculature of the canine thyroid gland was compared to that of the human and it was considered possible that the dog does not possess a caudal thyroid artery, as often described in the literature. The thyroid capsule was relatively thin in the dog and its trabeculae appeared histologically to be continuous with the tunica adventitia of the blood vessels. The intrinsic vascular pattern simulated the lobular structure and the blood vessels were named according to their relationship, course, and major area of supply inside the gland. The veins and lymphatics were satellite to the arteries and were designated homonymously. The lymph capillaries were more closely associated to the follicular epithelium than were the blood capillaries.