An endorcrine system involves all the glands in the body that make hormone. These glands are thehypothalamus, pituitary gland, pineal gland, thyroid and parathyroid gland, thymus, adrenals, pancreas ovaries/testes. They release hormone which act as chemical messenger to be carried through the blood stream into the target organ where its effect will manifest. In general endocrine system is ductless. This is regulated by feedback loop of hemeostasis.
