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.
The heart contains 4 chambers - the atria (left and right) and the ventricles (left and right). When the level of blood entering the heart increases, the heart muscle cells stretch. This stimulates the release of ANP by the atria and a similar hormone, BNP (brain natriuretic peptide) by the ventricles. ANP is effectively a âmaydayâ hormone. Cells in the heart walls secrete ANP to tell the rest of the body that the heart is experiencing a rising influx of blood. ANP counteracts renin (made by the kidneys), aldosterone (made by the adrenal gland), and angiotensin II, 3 hormones that increase blood pressure.