LESSON 1 BIOLOGY

• What does the renal artery do?

  Brings blood to the kidney
• What components are found in blood from the renal artery?

  Urea, toxins, O2, electrolytes, glucose
• Why is blood in the renal artery under pressure?

  To aid in ultrafiltration in Bowman’s capsule
• What does the renal vein do?

  Leaves the kidney after blood filtration
• What is the difference in blood composition between the renal artery and renal vein?

  Renal vein has less urea and more CO2
• What happens to blood pressure in the renal vein?

  It is not under pressure
• What is the role of the glomerulus in the nephron?

  It aids in ultrafiltration and filtrate formation
• How does the kidney help control blood pressure?

  By producing renin
• What is the function of renin?

  To increase blood pressure and retain sodium
• What does the renin-angiotensin-aldosterone system (RAAS) regulate?

  Blood volume and blood pressure
• What are the three major compounds in the RAAS?

  Renin, angiotensin II, and aldosterone
• What triggers the release of renin?

  When blood pressure falls in the glomerulus
• What does renin act on in the blood?

  Angiotensinogen
• Where is angiotensinogen produced?

  In the liver
• What does renin convert angiotensinogen into?

  Angiotensin I
• What is the role of angiotensin-converting enzyme (ACE)?

  To convert angiotensin I to angiotensin II
• What does angiotensin II stimulate the release of?

  Aldosterone
• How does aldosterone affect sodium and water reabsorption?

  Increases sodium reabsorption and water reabsorption
• What is the overall effect of the RAAS on blood volume and pressure?

  Increases blood volume and pressure
• What is the mechanism of the renin-angiotensin-aldosterone system (RAAS)?

  1. Renin is released when blood pressure falls.
  2. Renin converts angiotensinogen to angiotensin I.
  3. Angiotensin I is converted to angiotensin II by ACE.
  4. Angiotensin II stimulates aldosterone release.
  5. Aldosterone increases sodium and water reabsorption.
  6. This raises blood volume and pressure.
• What are the key differences between blood in the renal artery and renal vein?

  • Renal artery: High urea, toxins, O2, electrolytes
  • Renal vein: Low urea, high CO2, used O2
  • Renal artery: Under pressure, renal vein: not under pressure