In animals, a chemical secreted by an endocrine gland whose products are released into the circulating fluid. Plant hormones or synthetic hormones which are used only to alter or control various physiologic processes, e.g., reproductive control agents, are assigned only to the type 'Pharmacologic Substance'. Hormones act as chemical messengers and regulate various physiologic processes such as growth, reproduction, metabolism, etc. They usually fall into two broad classes, steroid hormones and peptide hormones.
(=> (Hormone ?Self)
(And (Exists (?A)
(And (Product-Of ?Self ?A)
(Secretion ?A)
(Exists (?B)
(And (Embodied-In ?A ?B)
(Endocrine-Gland ?B)))))
(Exists (?C)
(And (Affects ?Self ?C) (Physiologic-Function ?C)))))