Lecture 11/15: Renal Physiology Cont'd Flashcards
Final (49 cards)
What does it mean when creatinine clearance is reduced?
Renal function is reduced
How does chronic HTN above MAP of 150 effect the kidney?
AA will try to constrict but only to an extent –> increased RBF –> increased pressure in GC –> increase GFR –> increases UO
The GC is most effected by this
What are the 2 things in the kidney effected by HTN?
GC: Primary; prolonged high pressure = scarring; effects podocytes efficiency; widens fenestrations
AA: prolonged constriction = stiffening & prevents dilation when needed (BP drops)
T/F: increasing GFR will increase Reabsorption rate
F
You will reabsorb the same amount which is 124 ml/min
You will EXCRETE MORE
What happens to Reabsorption when GFR is decreased? why?
Reabsorption is increased
-fluids moving slowing thru the nephron
-more time in nephron = more time for reabsorption
What happens in the kidney when BP is decreased?
AA dilates –> GFR decreases –> reabsorption increases –> UO decreases
**MD senses… juxta releases renin –> constricts EA
Most vasoconstrictors, except ANG II, constricts ______ more than _______
AA
EA
T/F: ANG II constricts the AA & EA both equally
F
Constricts both, but constricts EA more
Prostaglandins preferentially dilate the ______ more
AA
NSAIDs preferentially vasoconstrict the ______ more. How?
AA
By inhibiting prostaglandins
T/F: There is reabsorption happening at every segment of the nephron
T
How much is reabsorbed at the PCT?
2/3
65%
Where is the MD located?
TAL
How does the MD work? Explain for low & high GFR
Acts as a sensor that counts Na+ & Cl- molecules as they pass by
Can detect a higher/lower number of Na/Cl and gauges GFR
Low: More ions are reabsorbed –> less ions make it to MD –> MD dectects that GFR is low –> juxta cells release renin –> ANG II increases –> EA constrict –> Pressure in GC increases –> GFR increases
High: normal ions are reabsorbed –> more ions make it to MD –> MD dectects that GFR is high –> juxta cells decrease release renin –> ANG II decreased –> EA relax –> Pressure in GC decreases –> GFR decreases
In addition to constricting to EA & AA, what other effects do ANG II have?
Increases Na reabsorption in PCT
This increases water reabsorption –> increase fluid volume –> increases BP
Describe the pathology if you had an increase in reabsorption of Na+ in the nephron. What could cause this? What is the Tx for this?
GFR could be normal, you’re just reabsorbing more more Na+
Less Na+ molecules at MD –> MD thinks GFR is low –> Juxta cells release Renin –> increase ANG II –> EA constricts –> Pressure in GC increases –> GFR increases (even tho it was fine)
This is bad. Creates high pressure at the GC which can destroy the GC –> destroys the nephron.
Causes: THE DIABETES!!!!
-Excess sugar intake causes the excess Na intake as well via the SGLT transporters in the PCT
Tx: ACE inhibitors (-prils)
ARBs (-sartan)
All of _____ & _______ should be filtered and reabsorbed at the proximal tubule if WNL
Glucose
Amino acids
What is the concentration of Na+ in the tubular cells?
14
What is the charge inside of the tubular cell?
-70 mV
Describe the amino acid transporter
1 Amino acid & 1 Na+
Cotransporter
-Located in PCT
-Apical side
What happens if you constant consume a high amount of amino acids?
Kidneys could be destroyed
Na+ reabsorption is increased with amino acids –> GFR is normal but Na+ at MD decreased –> Juxta releases Renin/ANGII
This causes pressure in the GC to increase which increases GFR more than needed
This is the same pathology as Diabetes
What is the main pathology in uncontrolled glucose (DM)?
Hyperfiltration of the GC
This causes damage to the GC which can ultimately destroy the Nephron putting strain on other nephrons –> this shortens the lifespan of the other nephrons
What food items are high in amino acids?
Steak
pre-workout
protein shakes
T/F: Glucose & amino acids can be absorbed in many places in the nephron
F
