Problem 3

Background and context

The thyroid is an endocrine gland located just below the larynx in the neck. It secretes the hormones thyroxine, also called, triiodothyronine, also called , and calcitonin. The thyroid-stimulating hormone called TSH is secreted by pituitary glands and it stimulates the thyroid gland to release thyroxine and triiodothyronine hormones. and hormones control metabolism and overall growth and development of a person. 

Two conditions arise when the thyroid gland is not functioning properly: hyperthyroidism and hypothyroidism. Hyperthyroidism is a condition in which the thyroid gland is overactive due to which there is overproduction of thyroid hormones. Hypothyroidism is a condition in which the thyroid gland is underactive due to which there is underproduction of thyroid hormones.