Ductless glands are the glands that release their secretion directly into the blood, not through any ducts.
Endocrine glands producehormones that are released directly into the blood.
The hormones secreted by these glands control growth, development, metabolic activities, and changes in secondary sexual characters.
The pineal gland, pituitary, thyroid gland, parathyroid gland, hypothalamus, adrenal glands, pancreas, ovaries, and testes are the main glands of the endocrine system.
Final answer: Endocrine glands are also called ductless glands.