Final answer:
Atrial natriuretic peptide (ANP), also known as atrial natriuretic hormone (ANH), is secreted from the heart's atria in response to increased blood volume, leading to a reduction in fluid retention and blood pressure.
Step-by-step explanation:
The hormone atrial natriuretic peptide (ANP) or atrial natriuretic hormone (ANH) is secreted from the heart following stretch stimuli from an increased blood volume. This hormone is produced by specialized endocrine cells in the walls of the atria of the heart. When high blood volume causes these cardiac muscle cells to stretch, ANP is released. ANP has several effects on the body; it acts on the kidneys to reduce Na+ reabsorption, leading to the excretion of sodium and water in the urine, consequently reducing blood volume and pressure. It also inhibits the release of renin and aldosterone, further supporting the decrease in fluid retention and blood pressure.\