Glands without ducts are called
Endocrine glands
Glands without ducts are called "ductless" or "endocrine" glands. They release their secretions directly into the bloodstream. Pituitary is the master endocrine gland which regulates the secretions of other endocrine glands such as pancreas, thyroid gland, gonads, adrenal gland, etc. The secretions of endocrine glands are called hormones.