Atrial natriuretic hormone (ANH) stimulates the kidneys to excrete salt and water in the urine. Why does it make sense that the heart is the source of ANH?

Question

A.  The heart is a major endocrine organ that releases several hormones.
B.  ANH helps regulate blood pressure, which is sensed by distension of the heart atria.
C.  The heart is conveniently close to the hypothalamus.
D.  Secretion of hormones by the heart makes it easy for them to enter the bloodstream.

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What type of thinking is required?

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Answer 1

B.  ANH helps regulate blood pressure, which is sensed by distension of the heart atria.

Clarify Question
What is the key concept addressed by the question?
        · Why does the heart produce ANH?
What type of thinking is required?
            o This is an analyze question because you have to consider each answer for validity in terms of the role of ANH and how it relates to the heart.

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What do you already know about atrial natriuretic hormone? What other information is related to the question?
        · Atrial natriuretic hormone (ANH) is secreted by the right atrium of the heart. ANH acts antagonistically to aldosterone, which promotes salt and water retention. Thus the effect of ANH is to increase salt and water excretion in the urine, which decreases blood volume and thus blood pressure.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Let us examine the answers. The heart is not a major endocrine gland, but it does secrete ANH. The heart is not conveniently close to the hypothalamus, which is in the brain. It is true that secretion from the heart is a convenient way for ANH to enter the bloodstream, but most hormones are released into the bloodstream via capillaries surrounding various glands located throughout the body. ANH, by increasing salt and water excretion in the urine, decreases the volume of water in the blood, which decreases blood pressure. It makes sense that stretch sensors in the atrium could respond to increased pressure by releasing ANH, which would reduce that pressure.

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
       · Answering this question correctly depended upon analyzing each potential answer for accuracy in terms of describing the role of ANH on the heart. If you got the answer correct, great! If not, which answer did you choose? Did you think that since the blood stream goes through the heart that secretion of hormones by the heart makes it easy for them to enter the bloodstream? That makes sense for ANH, which is secreted by the heart, but most hormones are not secreted by the heart, but by endocrine glands located throughout the body. ANH is not the only hormone produced by the heart. The heart also contains cells that release noradrenaline and dopamine, as well as oxytocin, although compared to the rest of the endocrine system, this is a small number of hormones.