Question

The atrial wall of our heart secretes

• A. GIP
• B. ANF
• C. ADH
• D. CCK

Answer 1

The correct option is B

ANF

The correct option is B

Explanation of the correct option:

1. The human heart is divided into four chambers: the right and left atriums, as well as the right and left ventricles.
2. The NPPA gene in humans encodes atrial natriuretic peptide (ANP), also known as atrial natriuretic factor (ANF), a natriuretic peptide hormone secreted by the cardiac atria.
3. The major function of ANP is to reduce the volume of extracellular fluid (ECF) via enhancing renal sodium excretion.
4. In the walls of the atria in the heart, cardiac muscle cells produce and secrete ANF. Volume receptors in these cardiac muscle cells operate to increase atrial wall stretching by raising blood volume.

Explanation of the incorrect option:

Option A:

GIP is produced in the gastrointestinal tract by endocrine cells.

Option C:

The posterior pituitary gland secretes ADH.

Option D:

CCK is produced in the gastrointestinal tract by endocrine cells.

Final answer: The atrial wall of our heart secretes ANF.