The Thyroid hormone

Initial Post: Explain the action of thyroid hormone. Your answer should contain the impact of the thyroid hormone on functions in the body.
Response 1: Discuss the negative feedback loop of thyroid function.
Response 2: Define the clinic presentation of hypothyroidism providing the pathophysiologic process underlying the clinical presentation.

Response 3:Define the clinical presentation of hyperthyroidism providing the pathological process underlying the clinical presentation. 

Please provide references in apa style.