Final answer:
The thyroid gland is responsible for creating hormones that control metabolism and is regulated by the pituitary gland through the secretion of TSH.
Step-by-step explanation:
The part of the body that makes the hormone controlling metabolism is the thyroid gland. The thyroid gland secretes thyroid hormones, which increase the metabolic rate in cells throughout the body. This gland is regulated by the pituitary gland, which is often referred to as the master gland of the endocrine system.
The pituitary gland secretes thyroid-stimulating hormone (TSH) that stimulates the thyroid gland to produce its hormones, primarily thyroxine (T4) and triiodothyronine (T3), both of which are critical in managing the body's metabolic processes.