glomerular function Flashcards

1
Q

4 major functions of kidneys

A
  1. excrete nitorgenous waste
  2. regulate volume
  3. synthesize hormones (renin, EPO)
  4. excrete exogenous compounds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is fucntional unit of kidney

A

nephron (glomerulus + tubule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is filtering unit of kidney

A

glomerulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is reabsorption unit of kidney

A

tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is blood path through kidney

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what percent of CO is renal blood flow

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is renal plasma flow

A

60% of blood so 0.6L/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how much of renal plasma flow is filtered

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is glomerular filtration rate

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

4 determinants of GFR

A
  1. cap surface area
  2. hydrostatic and oncitic pressures
  3. renal plasma flow (BP and afferent art resistance)
  4. efferent arteriolar resisitance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is filtration fraction

A

GFR/RPF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is general flitration fraction value

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is renal blood flow formula

A

art BP/vasular resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how do afferent arterioles regulate BP

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

3 things that affect aff resistance

A
  1. autoregulation
  2. sympathetics - constrict
  3. prostaglandins - dilate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

within what pressure does GFR remain constant

A

80-180mmHg

17
Q

what are 4 effects of prostaglandin on kidneys

A
  1. vasodilation
  2. incr renin
  3. antagonize ADH
  4. excrete Na
18
Q

what is effect of ASA and NSAIDs on prostaglandin

A

inhibit COX - not prostaglandins

19
Q

what will overall effect of ASA and NSAIDs be

A

extra reduction in renal blood flow

20
Q

what is effect of efferent arteriole resistance

A

increased pressure in GC and thus reduces filtration rate

21
Q

what gets filtered and what doesn’t

A

does: water and small solutes

doesn’t: large proteins

22
Q

what are 3 structural filtration barriers?

A
  1. endothelium
  2. glomerular basement membrane
  3. epoithelium
23
Q

2 main classes of kidney disease

A
  1. acute

2. chronic

24
Q

3 types of acute disease

A
  1. decreased perfusion
  2. blockage to urine flow
  3. acute damage to kidney tissue
25
4 types of chronic renal disease
1. metabolic - DM scarring 2. autoimmune - glomuerulonephritis 3. vascular - BP 4. genetic - polycyctic kidney
26
what are 3 options to measure Cr
1. Calculate GFR using 24 hour collection 2. compare plasma Cr to previous levels 3. use equatiosn
27
what is Cr
waste product made from muscle
28
what is plasma [Cr] formula
muscle/kidneys
29
what % of delivers Cr is filtered
20%
30
how much filter Cr is excreted
100%
31
what does Cr excreted =
urine [Cr] x urine vol/day
32
what does Cr filtered =
plasma [Cr] x GFR
33
** what does GFR =
(urine[Cr] x vol or urine/day)/plasma[Cr]
34
what happens to plasma [Cr] if GFR goes down
will go up until hits stready state
35
what is GFR compared to plasma [Cr]
GFR = 1/plasma [Cr]
36
how do you know when steady state acheived
no changes in plasma [Cr] over 2 days
37
what happens to GFR is plasma has gone up 3x
1/3