In the human body, the endocrine system plays a crucial role in regulating various physiological processes through the secretion of hormones. These hormones are chemical messengers that travel through the blood to tissues and organs, influencing numerous functions such as metabolism, growth, and mood. One of the key glands in the endocrine system is responsible for producing hormones that regulate the body's metabolic rate. Which gland is primarily responsible for the release of hormones that influence metabolism?