Several of the hormones of the endocrine system are involved in controlling the rate and direction of metabolism. Thymine , a hormone produced and released by the thyroid gland, plays a key role in determining how fast or slow the chemical reactions of metabolism proceed in a person's body.The pancreas secretes hormones that help determine whether the body's main metabolic activity at a particular time will be anabolism or catabolism. For example, after eating a meal, usually more anabolism activity occurs because eating increases the level of glucose - the body's most