Renal Flashcards
1
Q
functional unit of kidney
A
nephron
2
Q
nephron function
A
removes waste
mx ECF
3
Q
when do you start trending toward kidney failure/uremia
A
loss of >50% nephrons
4
Q
how many nephrons in kidney
A
1 million
5
Q
how many nephrons are lost after age 40
A
10% per decade
6
Q
how many nephrons do 80 year olds have
A
480-720k
7
Q
if you have decr nephrons you have _____ GFR
A
decr GFR
8
Q
CKD
A
acceleration of kidney ageing
9
Q
early nephron
A
glomerulus
proximal tubule
descending loop of henle
10
Q
proximal tubule function
A
reabsorb salts/H2O
11
Q
descending loop of henle
A
permeable to H2O
–reabsorption of H2O via osmosis
12
Q
as you move down the LoH, what happens to the [salt].
A
incr [salt] in ISF
13
Q
mid nephron
A
ascending loop of henle
distal convoluted tubule
collecting duct
14
Q
ascending LOH permeability
A
apearmeable to H2O
15
Q
ascending LOH function
A
absorbs NaCl/K+
dilutes
16
Q
counter current multiplier
A
ascending limb: pumps salt out
descending limb: incr H2O absorption
17
Q
distal convoluted tubule function
A
adjusts salts
modulates pH
favors reabsorption
18
Q
hyperkalemia reaction in distal convoluted tubule
A
DCT will secrete K+
– decr K+
19
Q
collecting duct function
A
adjusts H2O
20
Q
cortical collecting duct
A
upper 1/2
21
Q
medullary collecting duct
A
lower 1/2
22
Q
renal blood flow order
A
arcuate artery
interlobular artery
afferent arteriole
glomerulus
unfiltered
efferent arteriole
peritubular caps
vasa rector
interlobular vein
arcuate vein
renal vein
23
Q
what contorls the level of vasoconstriction and vasodialtion
A
afferent arteriole
24
Q
what surrounjds proximal and distal tubules
A
peritubular caps
25
function of peritubular caps
salt/H2O reabsorption
26
vasa rector includes
straight proximal tubule
ascending LoH
descending LoH
27
ascending LOH incr concentration of
salts (in ISF)
28
descending LOH incr concentration of
water
29
kidney size
0.5% of body mass
30
kidney blood flow
20% of CO
1L/min
31
why do kidneys need high blood flow
due to high filtration rate
high BF provides good control of ECF volume and osmolarity
32
what happens if BF is decr to kidneys
decr BF to paratubular caps
incr ischemia due to decr O2 supply with incr ATP demand
33
3 capillary beds
glomerulus
peritubular caps
vasa recta
34
glomerulus pressure
HIGH hydrostatic P
- promotes filtration
- incr peritubular oncotic P
35
peritubular caps pressure
HIGH oncotic P
- pulls salts/H2O INTO caps
36
vasa recta pressure
Low P
- osmotic gradient from counter current
37
urine producton steps
filtration
reabsorption by peritubular caps
secretion into tubular lumen
excretion
38
excretion equation
Exc = Fil - Reab + Sec
39
Filtered load equation
Fil = plasma [ ] x GFR
plasma [ ]:
Na+
Cl-
K+
H2O
Free Ca2+
Free Pi
40
fenestrated capillary endothelium
high permeability promotes filtration
41
basement membrane charge
(-) charge
42
basement membrane function
promotes filtration of small and (+) charged molecules
43
podocytes function
prevents filtration of large and (-) charged molecules
44
what glomular membrane changes incr filtration
sepsis
minimal change disease
45
what glomerular membrane changes decr filtration
endothelial cell swelling
basement remodeling
46
minimal change disease
decr podocytes
incr protein crossing
47
filtrate composition
low protein
no cells
no plts
48
plasma composition
high protein
cells
plts
49
sieving coefficient
[tubular fluid]/[plasma]
50
incr size _____ sieving coeff
decr sieving coeff
51
(+) charge _____ sieving coeff
incr sieving coeff
52
(-) charge ____ sieving coeff
decr sieving coeff
53
Pgc
glomerulus hydrostatic
== fluid OUT
54
Pi bs
bowman oncotic P
== Fluid OUT
55
Pi gc
glomerulus oncotic P
== fluid IN
56
P bs
bowman hydrostatic
== fluid IN
57
normal P gc
50 mmHg
58
normal Pi bs
0 mmHg
59
normal Pi gc
25 mmHg
60
normal P bs
10 mmHg
61
primary driver of net filtration pressure and GFR
P gc
62
NFP equation
NFP = (Pgc-Pbs) - (Pigc - Pibs)
63
(+) NFP
filtering OUT
64
(-) NFP
secreting IN
65
GFR
rate of formation of filtrate by kidneys per min
66
main difference between plasma and filtrate
protein higher in plasma than filtrate
67
clearance
volume of plasma that solutes occupied
vol of plasma/time
68
what % of plasma is delivered to kidney
20%
69
clearance equation
C = urinary excretion ([U]x [UV]) / Plasma
70
clearance units
mL/min
71
U
[solute] in urine
mg/mL
72
UV
vol urine
mL/min
73
P
[solute] in plasma
mg/mL
74
gold std marker of GFR
inulin
75
inulin sieving coeff
1
76
why is inulin great
does not alter GFR
it can only be filtered
77
inulin pro
high accuracy
used in drug research
78
inulin con
time intensive
expensive
79
most common way to estimate GFR
creatinine
80
creatinine is a metabolite of
creatinine phosphate
81
what happens to creatinine if you have decr renal function
incr creatinine
82
what is creatinine dependent on
muscle mass
83
alternative options to measure creatining
cystatin C
inulin
84
plasma Cr is _____ related to GFR
inversely releated
85
normal GFR
125 mL/min
86
Normal Cr
1 mg/dL
87
normal GFR per day
180 L/day
88
stage 1 CKD
>90
damage
normal GFR
89
Stage 2 CKD
60-89
damage
mild GFR
90
Stage 3a CKD
45-59
mild to mod GFR
91
Stage 3b CKD
30-45
mod GFR
92
Stage 4 CKD
15-30
sev GFR
93
Stage 5 CKD
<15 or dialysis
kidney failure
94
what stage CKD do you see K+/P+/Ca2+ increase
stage 4
95
blood flow to kidney
3.5 mL/min/gram of kidney
96
filtration fraction (FF)
% plasma filtered into renal tubules
97
FF equation
FF = GFR/renal plasma flow
98
renal plasma flow equation
RPF = 20% CO / (1-hct)
99
is O2 consumption critical for RBF regulation
No
high RBF is required for filtration, not metabolism
100
constrict afferent arteriole
decr BF
decr Pgc
decr GFR
101
dilate afferent arteriole
incr BF
incr Pgc
incr GFR
102
constrict efferent arteriol
decr BF
incr Pgc
incr GFR
103
how is GFR mx'd with low renal blood flow?
incr Pcg
104
dilate efferent arteriole
incr BF
decr Pgc
dec GFR
105
renal autoregulation
MAP 80-180 mmHg
106
MAP > 180mmHg
incr GFR
incr urinary volume
107
MAP < 80 mmHg
decr RBF
decr GFR
renal ischemia
108
neuroendocrine reulators
vasoconstrictors
vasodialtors
109
intrinsic renal autoregulation
myogenic mechanism
JGA (tuboglomerular feedback)
110
without regulation if you incr BP 25%, what happens
incr GFR 25%
- lg filtration
- incr work to reabsorb salts
- incr urinary output
111
constrictors _____ RBF
decr RBF
112
afferent constrictors
NE/Epi
adenosine (ATP)
113
NE/Epi released under:
pain
stress
exercise
hemorrhage
114
adenosine (ATP) released by:
macula densa
115
efferent constrictors
Ang2
ADH
116
what counters Ang2/ADH efferent constriction
NO/PG released by afferent arteriole
117
dilators ____ RBF
incr RBF
118
afferent dilators
renal PGL
ANP
119
both afferent and efferent dilators
NO
dopamine
120
renal PGL
keeps GFR constant despite constrictions
decr renin
decr aldosterone
121
ANP released
high atrial pressure
122
NO released
shear stress
keeps GFR constant despire constrictions
123
dopamine released
low doses preserve RBF during hemorrhage
124
myogenic mechanim function
ensures beat to beat constant RBF and GFR
125
incr arterial wall stretch causes
decr SBP
126
vasoconstriciton causes
incr DBP
127
high tubule flow
high NaCl in macula densa
= MD depolarization
128
low tubule flow
low NaCl in macula densa
= no Depolarization
129
AKI
kidney stops working abruptly
130
AKI responses
decr GFR
decr urine output
incr BUN
131
primary causes of AKI
pre-renal
intrinsic
post-renal
132
most common cause of AKI
pre-renal
133
prerenal AKI
hypovolemia
decr Q
decr ECFV
impaired autoreg
134
prerenal AKI causes
cardiac sx
bypass
135
intrinsic AKI
sepsis
necrosis/nephrotoxin
136
postrenal AKI
obstruction of urinary collection system
137
postrenal AKI causes
stones
tumors
ureter ligation
ureter compression
138
anesthesia can cause AKI
compound A from sevo
139
prevent AKI with sevo
FGF > 2L/min
