The anatomy and physiology of the thyroid gland was examined. The method of negative feedback to increase or decrease hormonal secretion of the thyroid was sketched, and the part played by the brain and pituitary examined. The structure of thyroxine hormone was handed out and the importance of iodine in the structure noted. The importance of iodine ingestion discussed and the labels of salt boxes viewed to show the addition of iodine. Showing the symptoms of hypothyroidism was used to begin the study of the function of the thyroid in the body. The first few symptoms examined were unexplained fatique, digestive upset, and irritability. This helped to show the major effect of thyroid hormone on metabolism, energy and mood.