A decrease in arterial blood pressure stimulates the kidneys to produce:Question 43Select one:a.ADHb.angiotensin IIc.aldosteroned.angiotensin Ie.renin

To answer the question, let's break down the process step by step:

1. Understanding the context: The question is about the physiological response to a decrease in arterial blood pressure and how the kidneys react to this change.

2. Key terms:

   • ADH (Antidiuretic Hormone): A hormone that helps the kidneys manage the amount of water in the body.
   • Angiotensin II: A peptide hormone that causes blood vessels to constrict, resulting in increased blood pressure.
   • Aldosterone: A hormone that increases the reabsorption of sodium and water in the kidneys, which increases blood volume and pressure.
   • Angiotensin I: A precursor to angiotensin II, converted by the enzyme ACE (Angiotensin-Converting Enzyme).
   • Renin: An enzyme secreted by the kidneys that starts the process leading to the production of angiotensin II.

3. Physiological response to decreased blood pressure:

   • When arterial blood pressure drops, the kidneys detect this change.
   • In response, the kidneys release renin.

4. Role of renin:

   • Renin is the initial enzyme in the renin-angiotensin-aldosterone system (RAAS).
   • It converts angiotensinogen (produced by the liver) into angiotensin I.
   • Angiotensin I is then converted to angiotensin II by ACE.

5. Conclusion:

   • The initial response of the kidneys to a decrease in arterial blood pressure is the production of renin.

Therefore, the correct answer is:

e. renin