Zoology - Chemical Coordination and Integration Question with Solution | TestHub

Hormones are non nutrient chemicals, which act as intracellular messengers and are produced in trace amounts. Endocrine cells are present in different parts of the gastrointestinal tract, e.g., gastrin, secretin, GIP. Atrial wall of our heart secretes a peptide hormone called ANF (Atrial Natriuretic Factor), $\mathrm{RH}/\mathrm{HH}$ are produced by hypothalamus. Adenohypophysis is not directly under neural control, it is under the control of hypothalamic hormones, brought by portal system.