The endocrine system is made up of glands that secrete hormones. Hormones are released into the bloodstream where they travel to tissue and generate a response. Hormones regulate metabolism, development, function, sleep, and mood. The glands that make up the endocrine system include the pineal, thyroid, adrenals, pituitary, parathyroid, pancreas, ovaries, and testes. These glands produce hormones such as cortisol, DHEA, estrogen, insulin, progesterone, testosterone, and adrenalin.