Renal Blood Flow Flashcards Preview

MSS - Renal Exam 1 > Renal Blood Flow > Flashcards

Flashcards in Renal Blood Flow Deck (37):
1

glomerular filtrate?

essentially free of blood cells and proteins, but otherwise identical to plasma

2

bowman capsule

squamous epithelium

3

total GFR

sum in all nephrons
-therefore, index of functioning renal mass

4

layers of glomerular membrane

inside > out

fenestrated capillary endothelium - highly permeable to water, dissolved solutes

glomerular basement membrane - collagen, proteoglycans with anionic charge

podocyte epithelium - slit pores between podocytes restrict large molecules

5

glomerular slit diaphragm

podocyte slit
-CD2AP and CD2-associated proteins
-nephrin molecules - are diaphragm

6

charge and filterability?

cationic is filtered more readily
anionic is filtered less readily

7

kidney disease

loss of negative charge on basement membrane before noticeable changes in renal structure

results in more filtration of proteins

8

GFR = ?

Kf x P-UF

Kf ultrafiltration coefficient (htdraulic conductivity times the surface area)

P-UF capillary ultrafiltration pressure

9

3 factors of GFR?

1 - hydraulic conductivity (Lp) of glomerular membrane (porosity)
2 - surface area of filtration
3 - Capillary ultrafiltration pressure

10

P-UF

determined by hydrostatic and colloid osmotic pressure in glomerular capillaries

P-BC - (P-GC + osmotic-GC) = P-UF**

osmotic-BC is approximately zero (no protein)

11

as move along glomerular capillary?

increased oncotic GC pressure

net ultrafiltration pressure decreases as move along

12

glomerular and peritubular starling forces?

?

13

?

?

14

?

?

15

?

?

16

altered Kf

mesangial cell contraction

17

altered P-UF

changes in P GC

18

P-GC determined by what

renal arterial BP
afferent arteriolar resistance
efferent arteriolar resistance

19

contraction of mesangial cells?

shorten capillary loop
lower Kf
lower GFR

20

P-GC

determined by changes in systemic arterial pressure P-A, afferent arteriolar resitance R-A, and efferent arteriolar resistance R-E

21

afferent arteriolar constriction

P-GC falls
lowers GFR
lower renal blood flow

22

efferent arteriolar constriction

pooling of blood in glomerular capillaries
increased P-GC
increased GFR

23

-

-

24

increased systemic arterial pressure?

increased P-GC
increased GFR
increased RBF

25

increased afferent arteriolar constriction?

decreased P-GC
decreased GFR
decreased RBF

26

increased efferent arteriolar constrition?

increased P-GC
increased GFR
decreased RBF

27

efferent arteriolar dilation?

decreased P-GC
decreased GFR
increased RBF

28

afferent arteriolar dilation?

increased P-GC
increased GFR
increased RBF

29

autoregulation

maintains GFR over MAP range of 80-170 mmHg

30

-

-

31

-

-

32

-

-

33

cortex

receives most RBF
-medulla receives less via vasa recta

34

sympathetic stimulation?

constriction of afferent
decreased RBF and GFR

granular cells then secrete renin

35

renin

causes ANG II increases

acts to restore blood pressure (systemic vasoconstriction)

36

ANG II

promotes arteriolar constriction (efferent > afferent)

raises BP, may stabilize GFR

also stimulates Na+ reabsorption in proximal tubule, ascending loop of henle, distal convoluted tubule, collecting duct

37

renal prostaglandins

dampen vasoconstriction due to ANG II and sympathetics

release is enhanced by ADH