First Aid Renal Physiology Flashcards
1
Q
Ureters pass under what structures?
A
Uterine artery (female) or vas deferens (males)
2
Q
Potassium inside the cell?
A
High (HIKIN’ = HIgh K Intracellular)
3
Q
60-40-20 rule
A
60% of body is water, 40% of body is ICF, 20% of body is ECF
4
Q
How do you measure plasma volume?
A
radiolabeled albumin
5
Q
How do you measure extracellular volume?
A
inulin
6
Q
what is the osmalarity of plasma?
A
290
7
Q
responsible for filtration of plasma according to size and net charge
A
glomerular filtration barrier
8
Q
what is the size barrier of glomerular filtration?
A
fenestrated capillary endothelium
9
Q
what is the negative charge barrier of glomerular filtration?
A
fused basement membrane with heparin sulfate
10
Q
what does the epithelial layer of glomerular filtration barrier consist of?
A
podocyte foot processes
11
Q
The charge barrier is lost in XXXX, resulting in albuminuria, hyporoteinuria, generalized edema, and hyperlipidemia
A
nephrotic syndrome
12
Q
how do you calculate clearance?
A
(urine concentration x urine flow rate)/plasma concentration
13
Q
when clearance is greater than GFR?
A
net secretion
14
Q
when clearance is less than GFR?
A
net reabsorbtion
15
Q
inulin clearance can be used to calculate GFR because it is
A
freely filtered and neither reabsorbed nor secreted
16
Q
normal GFR =
A
100 ml/min
17
Q
creatinine clearance slightly overestimates GFR because it is
A
moderately secreted by the renal tubules
18
Q
ERPF can be estimated using PAH clearance because
A
it is both filtered and actively secreted in the proximal tubule (all PAH entering the kidney is excreted)
19
Q
RBF =
A
RPF/(1-HCt)
20
Q
EFPF underestimates true RPF by
A
~10%
21
Q
FF =
A
GRF/RPF
22
Q
What dilates afferent arterioles?
A
Prostaglandins
23
Q
Prostaglandins dilate afferent arterioles –>
A
increased RPF, increased GFR, and no change in FF
24
Q
NSAID effect on kidney
A
block prostaglandins –> constrict afferent artery –> decreased RPF, decreased GFR, and no change in FF
25
Angiotensin II preferentially constricts efferent arteriole -->
decreased RPF, increased GFR, increased FF
26
ACE inhibitors preferential vasodilates efferent arteriole -->
increased RPF, decreased GFR, decreased FF
27
what is the effect on RBF, GFR, and FF with increased plasma protein concentration
NC
Decreased
Decreased
28
what is the effect on RBF, GFR, and FF with decreased plasma protein concentration?
NC
Increased
Increased
29
what is the effect on RBF, GFR, and FF with ureter constriction?
NC
Decreased
Decreased
30
filtered load =
GFR x Plasma concentration
31
Excretion rate =
urine flow x urine concentration
32
reabsorption =
filtered - excreted
33
secretion =
excreted - filtered
34
Glucose at a normal plasma level is completely reabsorbed in PCT by
Na_/glucose cotransport
35
glucose threshold
160
36
glucose Tm
350
37
Normal pregnancy reduces absorption of what in the PCT?
amino acids and glucose
38
amino acid clearance
sodium dependent transporters in PCT
39
deficiency of neutral amino acid (tryptophan) transporter; results in pellagra
Hartup's disease
40
PCT reabsorbs all glucose & AA, and most (5 things)
```
bicarb
sodium
chloride
phosphate
water
```
41
PCT absorption does what to tonicity?
isotonic
42
generated and secreted by PCT to act as a buffer for secreted H+
Ammonia
43
Inhibits Na+/phosphate cotransport --> phosphate excretion
PTH
44
PTH --> decreased phosphate by
increased excretion by decreasing reabsorption in PCT
45
ATII stimulates NA+/H+ exchange -->
increased sodium, water, and bicarb reabsorption, permitting contraction alkalosis
46
what percent of Na+ is reabsorbed in the PCT?
65-80%
47
thin descending loop of Henle is impermeable to
sodium (concentrating sdemgnet0
48
actively reabsorbs sodium, potassium, and chloride
TAL
49
TAL indirectly induces the paracellular reabsorption of [2 things] through (+) lumen potential generation by K+ backleak
magnesium and calcium
50
what percent of sodium is reabsorbed in the TAL
10-20%
51
what drugs work at the PCT?
ACE inhibitors,
| Carbonic anhydrase inhibitors
52
what drugs work at the TAL?
loop diuretics
53
TAL is impermeable to
water
54
actively reabsorbs sodium and potassium --> makes urine hypotonic
early DCT
55
what drugs work at the early DCT?
thiazide
56
Effect of PTH on early DCT?
increases calcium/sodium exchange --> increased calcium reabsorption
57
what percent of sodium is reabsorbed in the early DCT?
5-10%
58
what drugs work on the collecting tubule?
K+ sparing diuretics (amiloride, triamterene, spirolactone, eplerenone)
59
Collecting tubules reabsorb Na+ in exchange for secreting
K+ and H+
60
regulates collecting tubule reabsorption of Na+ in exchange for K+ and H+ secretion
aldosterone
61
acts on mineralocorticoid receptor in collecting tuble--> insertion of Na+ channel on luminal side
aldosterone
62
acts at V2 receptor in principal cell in collecting tubule
ADH
63
ADH --> insertion of
aquaporin H2 channels on luminal side of principal cell in collecting tubule
64
percent of Na+ reabsorbed in collecting tubule
3-5%
65
TF/P > 1 when
solute is reabsorbed less quickly than water
66
TF/P = 1 when
solute and water are reabsorbed at the same rate
67
TF/P <1 when
solute is reabsorbed more quickly than water
68
tubulan inulin increases in concentration along the PCT as a result of
water reabsorption
69
Renin responds to three things
decreased BP, decreased Na+ delivery, increased sympathetic tone
70
JG cells secrete renin in response to
low BP
71
macula densa tells JG cells to secrete renin in response to
low Na+ (Cl-) delivery
72
what receptors tell JG cells to secrete renin in response to increased sympathetic tone?
beta-1
73
AT II has six effects
1. vasoconstriction of vascular smooth muscle
2. vasoconstriction of efferent arteriole
3. ldosterone
4. ADH
5. Increased proximal tubule Na+/H+ activity
6. Stimulates hypothalamus
74
What is the rationale of AT II preferential constriction of efferent arteriole
increase FF to preserve GFR in low-volume sttes
75
aldosterone is produced by
adrenal gland
76
aldosterone effects
1. increased Na+ and Na+K+ pump insertion in principal cells
| 2. enhanced K+ and H_ excretion
77
aldosterone --> enhanced K+ secretion where?
principal cell K+ channels
78
aldosterone --> inc H+ secretion where
intercalated cell H+ channels
79
net effect of aldosterone
creats favorable Na+ gradient for Na+ and H20 reabsorption
80
what produces ADH?
posterior pituitary
81
ADH --> increased H2O channel insertion in
principal cells
82
net effect of ADH
increased H2O reabsorption
83
affects baroreceptor function; limits reflex bradycardia; helps maintain blood volume and BP
angiotensin II
84
angiotensinogen is produced by the
liver
85
angiotensinogen --> angiotensin I
Renin
86
angiotensin I --> angiotensin II
ACE
87
ACE inhibits
bradykinin
88
ACE is produced by the
lungs
89
Released from atria in response to increased volume; may act as a check on RAA system; relaxes vascular smooth muscle via cGMP, causing increased GFR and decreased renin
ANP
90
primarily regulates osmolarity but also responds to low blood volume, which takes precedence over osmolarity
ADH
91
primarily regulates blood volume;
Aldosterone
92
in low-volume states, what acts to protect blood volume
BOTH aldosterone and ADH
93
beta blocker effect on kidney
inhibit beta-1 receptors of the JGA, causing decreased renin release
94
released by interstitial cells in the peritubular capillary bed in response to hypoxia
EPO
95
what cells produce epo
renal peritubular intersitial cells
96
what cells convert 25-OH vitamin D to its active form
proximal tubule cells
97
what enzyme converts vitamin D to its active form?
1alpha hydroxylase
98
what stimulates 1-alpha-hydroylase production?
PTH
99
secreted by JG cells in response to decreased renal arterial pressure and increased renal sympathetic discharge (beta1 effect)
renin
100
paracrine secretion vasodilates the afferent arterioles to increase GFR
prostaglandins
101
NSAIDs can cause acute renal failure by inhibiting the renal production of
prostaglandins
102
4 kidney endocrine functions
1. epo
2. 1,25-(OH)2 vitamin D
3. Renin
4. Prostaglandins
103
6 hormones act on kidney
ANP, PTH, Renin, AT II, Aldosterone, ADH
104
Secreted in response to increased atrial pressure.
Atrial natriuretic peptide (ANP)
105
Causes increased GFR and increased sodium filtration with no compensatory Na+ reabsorption in distal nephron --> Na+ loss and volume loss
ANP
106
PTH is secreted in response to three things
decreased plasma calcium
increased plasma phosphate
decreased plasma 1.25-(OH)2 vitamin D
107
PTH causes increased calcium reabsorption where?
DCT
108
PTH causes decreased phosphate reabsorption where?
PCT?
109
PTH has 4 effects:
increased calcium reabsorption (DCT)
decreased phosphate reabsorption (PCT)
increased 1,25-(OH)2 vitamin D production
increased calcium and phosphate absorption from gut
110
Angiotensin II is synthesized in response to:
decreased BP
111
Renin is synthesized in response to:
decreased blood volume
112
Aldosterone is synthesize in response to:
decreased blood volume (via AT II)
| increased [K+]
113
Aldosterone causes three effects
1. Increased sodium reabsorption
2. Increased K+ secretion
3. Increased H+ secretion
114
Causes efferent arteriole constriction (--> inc GFR and FF) but with compensatory Na+ reabsorption in proximal and distal nephron
AT II
115
Preservation of renal function in low-volume state (increased FF) with simultaneous NA+ reabsorption (both proximal and distal) to decreased additional volume loss
AT II
116
Secreted in response to increased plasma osmolarity and decreased blood volume
ADH
117
Binds to receptors on principal cells --> increased number of water channel channels --> increased H2O reabsorption
ADH
