Ductless glands are glands that secrete their product directly onto a surface rather than through a duct. Examples are the goblet cells in the epithelial surface of the digestive, respiratory, urinary and reproductive systems. Many endocrine glands are also ductless glands, as they secrete the hormones they produce directly into the blood or lymph system so it will be circulated to the entire body. The pineal gland, the thymus gland, the pituitary gland, the thyroid gland, the spleen, and the two adrenal glands are all ductless glands.