For 10 points, name this organ of the endocrine system, a swelling of which is caused by a lack of iodine and is called goiter.
Hashimoto's disease in this organ results in under production of this organ's hormones, which results in cretinism. By contrast, hyperactivity of this organ is known as Graves' disease. TSH stimulates this organ to produce T3 and T4, and another important hormone produced by this gland opposes insulin, calcitonin. For 10 points, name this organ of the endocrine system, a swelling of which is caused by a lack of iodine and is called goiter.
Hashimoto's disease in this organ results in under production of this organ's hormones, which results in cretinism.
{thyroid}