Thyroiditis (Hashimoto's disease). Light micrograph of a section through a thyroid gland with the autoimmune disorder Hashimoto's disease. The thyroid is an endocrine gland found in the neck, responsible for the production of hormones controlling the body's metabolism. At right is part of a germinal centre, an area of tissue, usually found in lymph nodes, where cells of the immune system rapidly divide. The white blood cells produced in the germinal centre attack the thyroid gland, causing hypothyroidism (lowered thyroid function). Treatment involves the use of levothyroxine, a synthetic thyroid hormone. Magnification: x570 when printed at 10 centimetres wide.