Renal Blood Flow

Question 1

glomerular filtrate?

Answer 1

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

Question 2

bowman capsule

Answer 2

squamous epithelium

Question 3

total GFR

Answer 3

sum in all nephrons

-therefore, index of functioning renal mass

Question 4

layers of glomerular membrane

Answer 4

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

Question 5

glomerular slit diaphragm

Answer 5

podocyte slit

• CD2AP and CD2-associated proteins
• nephrin molecules - are diaphragm

Question 6

charge and filterability?

Answer 6

cationic is filtered more readily

anionic is filtered less readily

Question 7

kidney disease

Answer 7

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

results in more filtration of proteins

Question 8

GFR = ?

Answer 8

Kf x P-UF

Kf ultrafiltration coefficient (htdraulic conductivity times the surface area)

P-UF capillary ultrafiltration pressure

Question 9

3 factors of GFR?

Answer 9

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

Question 10

P-UF

Answer 10

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)

Question 11

as move along glomerular capillary?

Answer 11

increased oncotic GC pressure

net ultrafiltration pressure decreases as move along

Question 12

glomerular and peritubular starling forces?

Answer 12

?

Question 13

?

Answer 13

?

Question 14

?

Answer 14

?

Question 15

?

Answer 15

?

Question 16

altered Kf

Answer 16

mesangial cell contraction

Question 17

altered P-UF

Answer 17

changes in P GC

Question 18

P-GC determined by what

Answer 18

renal arterial BP
afferent arteriolar resistance
efferent arteriolar resistance

Question 19

contraction of mesangial cells?

Answer 19

shorten capillary loop
lower Kf
lower GFR

Question 20

P-GC

Answer 20

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

Question 21

afferent arteriolar constriction

Answer 21

P-GC falls
lowers GFR
lower renal blood flow

Question 22

efferent arteriolar constriction

Answer 22

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

Question 23

-

Answer 23

-

Question 24

increased systemic arterial pressure?

Answer 24

increased P-GC
increased GFR
increased RBF

Question 25

increased afferent arteriolar constriction?

Answer 25

decreased P-GC
decreased GFR
decreased RBF

Question 26

increased efferent arteriolar constrition?

Answer 26

increased P-GC
increased GFR
decreased RBF

Question 27

efferent arteriolar dilation?

Answer 27

decreased P-GC
decreased GFR
increased RBF

Question 28

afferent arteriolar dilation?

Answer 28

increased P-GC
increased GFR
increased RBF

Question 29

autoregulation

Answer 29

maintains GFR over MAP range of 80-170 mmHg

Question 30

-

Answer 30

-

Question 31

-

Answer 31

-

Question 32

-

Answer 32

-

Question 33

cortex

Answer 33

receives most RBF

-medulla receives less via vasa recta

Question 34

sympathetic stimulation?

Answer 34

constriction of afferent
decreased RBF and GFR

granular cells then secrete renin

Question 35

renin

Answer 35

causes ANG II increases

acts to restore blood pressure (systemic vasoconstriction)

Question 36

ANG II

Answer 36

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

Question 37

renal prostaglandins

Answer 37

dampen vasoconstriction due to ANG II and sympathetics

release is enhanced by ADH