Which one of the following hormones reduces blood pressure?

The hormone that reduces blood pressure is atrial natriuretic factor (ANF).

 Atrial natriuretic factor (ANF), also known as atrial natriuretic peptide (ANP), is a hormone released by the atria of the heart in response to increased blood volume and pressure. Its primary function is to regulate blood pressure and fluid balance in the body.

When blood volume and pressure increase, the atrial cells release ANF into the bloodstream. ANF acts on the kidneys and blood vessels to promote the excretion of sodium and water. By promoting the loss of sodium and water in the urine, ANF reduces blood volume, which, in turn, leads to a decrease in blood pressure. It also causes vasodilation, leading to a decrease in blood pressure.

(2) Aldosterone increases the reabsorption of sodium and water in the kidneys, leading to an increase in blood volume and blood pressure.

(3) Angiotensin causes vasoconstriction (narrowing of blood vessels) and promotes the release of aldosterone, leading to an increase in blood pressure.

(4) Antidiuretic hormone (ADH), also known as vasopressin, increases water reabsorption in the kidneys, thereby increasing blood volume and blood pressure. It also causes vasoconstriction, leading to an increase in blood pressure.