AEMCA Practice Exam

From which organ is angiotensinogen released?

1. Heart

2. Liver

3. Lungs

4. Spleen

The correct answer is: Liver

Angiotensinogen is a precursor protein produced and released by the liver. This protein plays a crucial role in the renin-angiotensin system, which regulates blood pressure and fluid balance in the body. When blood pressure drops or there is reduced blood flow to the kidneys, renin, an enzyme secreted by the kidneys, converts angiotensinogen into angiotensin I. Subsequently, angiotensin I is further converted into angiotensin II, a potent vasoconstrictor that increases blood pressure and stimulates the release of aldosterone, leading to increased sodium and water retention. The other organs listed do not produce angiotensinogen. The heart primarily functions in pumping blood and does not have a role in producing this protein. The lungs are involved in gas exchange and the regulation of blood pH, but they are not involved in the production of angiotensinogen. The spleen is part of the immune system and functions in filtering blood and recycling iron but does not produce angiotensinogen. Thus, the liver is the correct organ associated with the release of angiotensinogen.