mediates such hormonal response as the mobilization of

stored energy (the breakdown of carbohydrates in liver or

triglycerides in fat cells stimulated by β-adrenomimetic

catecholamines), conservation of water by the kidney

(mediated by vasopressin), Ca 2+ homeostasis (regulated by

parathyroid hormone), and increased rate and contractile force

of heart muscle (β-adrenomimetic catecholamines).