Glands are organs in the body that secrete substances, such as hormones or enzymes, for use elsewhere in the body or for elimination from the body. There are two main types of glands: exocrine glands and endocrine glands.
Exocrine glands secrete their products into ducts, which then carry the secretions to the surface of the body or into body cavities. Examples of exocrine glands include sweat glands, salivary glands, and mammary glands.
Endocrine glands secrete hormones directly into the bloodstream. These hormones then travel to target organs or tissues where they regulate various physiological processes. Examples of endocrine glands include the pituitary gland, thyroid gland, and adrenal glands.