ABSTRACT
The blood supply of the thyroid is symmetric bilaterally. The superior thyroid artery is a branch of the external carotid artery, whilst the inferior thyroid artery is a branch of the thyrocervical trunk. Thyroid gland, being an endocrine gland, is susceptible to both disorders of structure and function and the may lead to local or systemic effects. A clear understanding of the location, course and function of the nerves is essential to the thyroid surgeon and the team caring for these patients pre- and post-operatively. The external branch descends on the lateral aspect of the larynx deep to the sternothyroid to supply the cricothyroid muscle. The thyroid is innervated by the autonomic nervous system, the vagus and the sympathetic trunk providing the parasympathetic and sympathetic fibres, respectively. The thyroid gland, being an endocrine organ, may be affected by endocrine activity disorders.
