Image: Seals are consumers. An ecosystem is made up of animals, plants and bacteria as well as the physical and chemical environment they live in. The living parts of an ecosystem are called factors while the environmental factors that they interact with are called abiotic factors.
Atrial natriuretic peptide (ANP), also called atrial natriuretic factor (ANF), atrial natriuretic hormone (ANH), cardionatrine, cardiodilatin (CDD), or atriopeptin, is a powerful vasodilator, and a protein (polypeptide) hormone secreted by heart muscle cells.
1 Epinephrine (generally a hormone) /norepinephrine (generally a neurotransmitter) 2  Released as a neurotransmitter by the sympathetic system & as a hormone by the adrenal medulla in response to sympathetic activation.  Remember that we have two major kinds of receptors here - the alpha's and the beta's.