Final answer:
The endocrine cells of the heart are stimulated to secrete natriuretic peptides in response to increased blood volume. Natriuretic peptides, such as atrial natriuretic peptide (ANP), act on the kidneys to reduce sodium and water reabsorption, promoting their excretion in the urine. ANP also decreases renin and aldosterone release, further preventing water retention.
Step-by-step explanation:
The heart possesses specialized cardiac muscle cells in the walls of the atria that release the hormone atrial natriuretic peptide (ANP) in response to increased blood volume. When the blood volume increases and stretches the cells, ANP is secreted.
ANP acts on the kidneys to reduce the reabsorption of sodium and water, promoting their excretion in the urine. ANP also decreases the release of renin and aldosterone, further preventing water retention. Overall, ANP reduces blood volume, blood pressure, and sodium concentration in the blood.