SM 189a/190a - Functional Renal Anatomy and Glomerular Filtration, Regulation

Question 1

If solute delivery to the juxtaglomerular apparatus is too high, which cells respond?

What is the response?

Answer 1

• Macula densa senses increase in solute (Na+) delivery
• Macula densa releases adenosine
• Adenosine causes extraglomerular mesangial cells to contract and cause vasocaonstriction of the afferent arteriole

Question 2

What is the equation for clearance (kidney)?

Answer 2

Question 3

If solute delivery to the juxtaglomerular apparatus is too low, which cells respond?

What is the response?

Answer 3

• Macula densa senses decrease in solute (Cl-) delivery and/or flow
• Signals to the granular cells in the wall of the afferent arteriole
• Granular cells release renin
• Renin secretion -> Increased Angiotensin II production
• Angiotensin II ->
  
  • Increased Na/H exchange
  • Constriction of the efferent arteriole
  • Aldosterone secretion -> Na+ reabsorption

Question 4

Where in the RAA system do beta blockers act?

What do they do?

Answer 4

Beta-1 adrenergic stimulation causes renin release

Beta blockers prevent renin release, thus inhibiting the RAA system that produes Angiotensin II