glomerular function

Question 1

4 major functions of kidneys

Answer 1

1. excrete nitorgenous waste
2. regulate volume
3. synthesize hormones (renin, EPO)
4. excrete exogenous compounds

Question 2

what is fucntional unit of kidney

Answer 2

nephron (glomerulus + tubule)

Question 3

what is filtering unit of kidney

Answer 3

glomerulus

Question 4

what is reabsorption unit of kidney

Answer 4

tubule

Question 5

what is blood path through kidney

Answer 5

renal art>smaller art>afferent arterioles>glom>eff arterioles>peritubular caps>small veins>renal veins

Question 6

what percent of CO is renal blood flow

Answer 6

20% of 5l/min = 1L per min

Question 7

what is renal plasma flow

Answer 7

60% of blood so 0.6L/min

Question 8

how much of renal plasma flow is filtered

Answer 8

20%

Question 9

what is glomerular filtration rate

Answer 9

rate at which fluid is filtered from glom to bowman’s (120ml/min)

Question 10

4 determinants of GFR

Answer 10

1. cap surface area
2. hydrostatic and oncitic pressures
3. renal plasma flow (BP and afferent art resistance)
4. efferent arteriolar resisitance

Question 11

what is filtration fraction

Answer 11

GFR/RPF

Question 12

what is general flitration fraction value

Answer 12

20% and constant, so if RPF rises, so does GFR

Question 13

what is renal blood flow formula

Answer 13

art BP/vasular resistance

Question 14

how do afferent arterioles regulate BP

Answer 14

as BP goes up, they constrict to reduce flow and keep constant

Question 15

3 things that affect aff resistance

Answer 15

1. autoregulation
2. sympathetics - constrict
3. prostaglandins - dilate

Question 16

within what pressure does GFR remain constant

Answer 16

80-180mmHg

Question 17

what are 4 effects of prostaglandin on kidneys

Answer 17

1. vasodilation
2. incr renin
3. antagonize ADH
4. excrete Na

Question 18

what is effect of ASA and NSAIDs on prostaglandin

Answer 18

inhibit COX - not prostaglandins

Question 19

what will overall effect of ASA and NSAIDs be

Answer 19

extra reduction in renal blood flow

Question 20

what is effect of efferent arteriole resistance

Answer 20

increased pressure in GC and thus reduces filtration rate

Question 21

what gets filtered and what doesn’t

Answer 21

does: water and small solutes

doesn’t: large proteins

Question 22

what are 3 structural filtration barriers?

Answer 22

1. endothelium
2. glomerular basement membrane
3. epoithelium

Question 23

2 main classes of kidney disease

Answer 23

1. acute

2. chronic

Question 24

3 types of acute disease

Answer 24

1. decreased perfusion
2. blockage to urine flow
3. acute damage to kidney tissue

Question 25

4 types of chronic renal disease

Answer 25

1. metabolic - DM scarring
2. autoimmune - glomuerulonephritis
3. vascular - BP
4. genetic - polycyctic kidney

Question 26

what are 3 options to measure Cr

Answer 26

1. Calculate GFR using 24 hour collection
2. compare plasma Cr to previous levels
3. use equatiosn

Question 27

what is Cr

Answer 27

waste product made from muscle

Question 28

what is plasma [Cr] formula

Answer 28

muscle/kidneys

Question 29

what % of delivers Cr is filtered

Answer 29

20%

Question 30

how much filter Cr is excreted

Answer 30

100%

Question 31

what does Cr excreted =

Answer 31

urine [Cr] x urine vol/day

Question 32

what does Cr filtered =

Answer 32

plasma [Cr] x GFR

Question 33

** what does GFR =

Answer 33

(urine[Cr] x vol or urine/day)/plasma[Cr]

Question 34

what happens to plasma [Cr] if GFR goes down

Answer 34

will go up until hits stready state

Question 35

what is GFR compared to plasma [Cr]

Answer 35

GFR = 1/plasma [Cr]

Question 36

how do you know when steady state acheived

Answer 36

no changes in plasma [Cr] over 2 days

Question 37

what happens to GFR is plasma has gone up 3x

Answer 37

1/3