Flashcards in Renal Basics Deck (20):
1
9 jobs of the kidney:
1. Filtration
2. blood pressure
3. Na+ homeostasis
4. K+ homeostasis
5. H2O homeastasis
6. Bone/mineral -- vit D, PO4, Ca2+
7. Acid/Base
8. RBC production and regulation (EPO)
9. gluconeogenesis
2
% of CO that gets first pass renal flow?
20%
** ~1000 mL blood per min!!!
3
Normal RPF (renal plasma flow):
600 mL/min
or 60% of the 1000 mL total renal blood flow
**40% of blood is RBCs
4
3 structure that create the barrier between glomerular capilary lumen and Bowman's space:
1. capillary endothelium
2. basement membrane
3. podocytes
5
What is allowed to pass through glomerlular capillary endothelium?
anything except protein and cells
6
Aside from size, what affects passage through BM and podocyte slits?
charge
**negative charge make passage of negatively charged particle (ie. albumin) more difficult
7
Size cutoff for freely filtered plasma components?
= 7,000 D
Na- 23 D
K- 39 D
urea- 60 D
Creatinine- 113 D
8
Size cutoff for plasma components to be completely excluded from filtration?
> 70,000 D
albumin= 66,000 D (and is neg charged so normally does not filter)
9
Normal glomerular capillary pressure:
60 mmHg
10
Normal Bowman's space pressure:
15 mmHg
11
Normal glomerular capillary oncotic pressure:
29 mmHg
12
Normal Bowman's space oncotic pressure:
0 mmHg
13
Net ultrafiltration pressure=?
(glomerular cap pressure + Bowman's space oncotic pressu [both favor filtration]) - (Bowman's space pressure + glomerular capillary oncotic pressure [both favor absorption])
Normal: (60 + 0) - (15 + 29)= 16 mmHg
14
Normal GFR?
180 L/day
125 mL/min
15
normal plasma flow in Efferent artery (ml/min)?
475 mL/min
600 mL (afferent) - 125 mL filtered by glomeruli
16
Prostaglandins effect on glomeruli?
dilate afferent arteriole
17
NE effect on glomeruli?
constrict afferent and efferent arterioles
18
Angiotensin II effect on glomeruli?
constrict afferent and efferent arterioles
**more efferent???
19
General equation for GFR:
GFR= excretion rate of unique solute (not reabsorbed)/(plasma conc of unique solute)
20