The endocrine system consists of glands that secrete hormones directly into the bloodstream to regulate bodily functions. The central glands include the hypothalamus, pituitary gland, and pineal gland located in the brain. The hypothalamus controls body processes like temperature and hunger and communicates with the pituitary gland, which sends signals to other glands. Peripheral glands outside the brain include the thyroid gland, which regulates metabolism, and the pancreas, which produces insulin to regulate blood sugar.