Lecture 5 Final Flashcards
,How does the autoregulation work in the system?
Increase in pressure > increase glomerular pressure > increase GFR > increase UOP > lowers systemic pressure
What makes it a good thing to have a slowed down velocity in the ascending vasa recta?
after reabsorption, as it goes up to a lower concentration, there’s an opportunity for the proteins to move back into the renal interstitium. If the flow is too fast, that chance is decreased and leads to a “washout”
What happens to the kidneys during chronic HTN?
Unregulated high BP: (Unlikely)
If the Pressure is “200mmHg”, the AA will constrict but not enough to reduce pressure to the GCs “90mmHG” instead of 60mmHg showing an increase of +30 NFP when originally it’s 10mmHG so now it’s 40mmHG.
Kf = 12.5 x 40 = 500ml/min. 124ml is reabsorbed leaving a urine output of 376ml/min
What happens to normal kidney autoregulation if the BP is low?
the AA will relax, causing an increase in flow to the GCs pressure
What happens to the autoregulation after exposure to prolonged HTN
the arterioles tend to stiffen and elasticity is decreased so it is unable to handle low BP. Podocytes will also start to show wear and tear and structures to the GCs are weakened. Fenestrations and slit pores may be bigger than usual as well.
What is damaged the most when exposed to prolonged HTN?
Glomerular Capillary beds
Is it uncommon to have the efferent arteriole constrict while the afferent arteriole dilate?
No, this is usually how it goes.
What “agent” affects the efferent arteriole more?
Angiotensin II
Which drugs affect the afferent arteriole more?
B-blockers, Ca Ch Blockers
Which drugs affect the afferent and efferent arterioles?
Pressors
T/F: Angiotensin II only constricts the efferent arteriole.
False, it constricts both but mainly constricts the efferent arteriole more.
What effects does a reduced Angiotensin II have?
Dilated efferent arteriole.
T/F: Reabsorption occurs throughout the renal tubule segment.
True, just different segments reabsorb more than others.
What is 2/3 reabsorbed in the PCT?
Water
What happens to Cr concentration if it is not reabsorbed in the PCT?
Increases in the tubule the further it gets.
If there’s a high concentration of Na+ and Cl- at the Macula Densa, the GFR is?
Increased
If the Na+ and Cl- concentration at the Macula Densa is low, this means the GFR is?
decreased