Endocrine glands are specialized organs in the body that produce and release hormones directly into the bloodstream. These hormones act as chemical messengers, regulating various bodily functions such as growth, metabolism, and mood. Key endocrine glands include the pituitary gland, thyroid gland, and adrenal glands. Unlike exocrine glands, which secrete substances through ducts, endocrine glands release hormones directly into the circulatory system. This allows hormones to travel throughout the body and target specific organs or tissues, influencing processes like reproduction, stress response, and blood sugar regulation.