Endocrine glands are ductless glands that release hormones directly into the blood. Major endocrine glands include the pituitary gland, thyroid gland, adrenal glands, pancreas, and gonads (ovaries and testes). Unlike exocrine glands, which release their secretions through ducts to the outside of the body or onto a surface within the body, endocrine glands are highly vascularized to facilitate hormone entry into the bloodstream.
