Choose the correct answer from the options given in the bracket.
A chemical messenger produced by endocrine glands and secreted directly into the bloodstream to exert a specific effect on a distant part of the body is called ..........
(Cushing's syndrome, enzyme, acromegaly, endocrine, exocrine, diabetes mellitus, diabetes insipidus, myxedema, goitre, cretinism, hormone, enzyme)