2019 Volume 56 Issue 3 Pages 132-137
The thyroid gland is dually innervated by sympathetic and parasympathetic (superior laryngeal nerve: SLN) nerves. However, their contribution to the regulation of the secretory function of the thyroid remains unclear. Recently, our experiments, performing of electrical stimulation of cervical sympathetic trunks and SLNs and collecting the thyroid venous blood of anesthetized rats, showed that hormonal secretion from the thyroid gland is rapidly and antagonistically regulated by sympathetic and parasympathetic efferent nerve activity, suggesting that excitation of the myelinated afferent fibers of SLN may induce reflex increases in hormonal secretion from the thyroid gland. We also found that a natural stimulation triggering this kind of reflex is mechanical stimulation of the pharynx.