Week 5 - Kidneys and BP

Question 1

Explain the Renin-Angiotensin-Aldosterone System (RAAS)

Answer 1

Renin Release: Low blood pressure or low sodium levels prompt the kidneys to release renin.

Angiotensin I Formation: Renin converts angiotensinogen (from the liver) into angiotensin I.

Angiotensin II Creation: Angiotensin-converting enzyme (ACE), mostly in the lungs, turns angiotensin I into angiotensin II.

Actions of Angiotensin II: This powerful compound raises blood pressure by constricting blood vessels and signaling the adrenal glands to release aldosterone.

Aldosterone Effect: Aldosterone prompts the kidneys to retain sodium and water, increasing blood volume and pressure.

Question 2

Sodium and Water Regulation

Answer 2

The kidneys adjust blood pressure by controlling water retention through sodium reabsorption. More sodium reabsorbed leads to more water retained, increasing blood volume and pressure.

Question 3

Explain Direct Regulation of Blood Volume

Answer 3

By filtering blood and adjusting the urine output, the kidneys directly regulate the total volume of blood, affecting blood pressure.

Question 4

Atrial Natriuretic Peptide (ANP)

Answer 4

Released by the heart when blood volume is too high, ANP lowers blood pressure by causing the kidneys to excrete more sodium and water, reducing blood volume.

Question 5

How does the Kidney regulate BP? (4)

Answer 5

Renin-Angiotensin-Aldosterone System (RAAS), Sodium and Water Regulation, Direct Regulation of Blood Volume, Atrial Natriuretic Peptide (ANP)