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.
Activation of sympathetic adrenergic nerves to the heart releases norepinephrine that binds to adrenergic receptors (primarily beta-adrenoceptors), which increases heart rate (positive chronotropy), contractility (positive inotropy) and velocity of electrical impulse conduction (positive dromotropy).