ILE U4 D1 Flashcards
1
Q
Adults are _% water
A
50-60%
2
Q
Children are _% water
A
75%
3
Q
The elderly is _% water
A
45%
4
Q
Blood plasma has high concentrations of
A
Na, Cl, Bicarb, protein
5
Q
The IF has high concentrations of
A
Na, Cl, bicarb, lower level of protein
6
Q
ICF has high levels of
A
K, phos, mag, and protein
7
Q
How does H2O move across cell membranes?
A
Passively, largely through osmosis and facilitated diffusion
8
Q
H2O movement depends on
A
The concentration of the environment
9
Q
Passive movement occurs __ the concentration gradient
A
down (high -> low)
10
Q
Channels offer ___ and ___
A
insulated and larger passageways for molecules to cross
11
Q
Ligand gating
A
Channel opens in response to (ligand) binding
12
Q
Voltage gating
A
Channel opens in response to change in membrane potential
13
Q
Posttranslational modification
A
Channel gates in response to modification (like phosphorylation)
14
Q
_K:_Na in K:Na pump?
A
2K:3Na
15
Q
Isotonic solution
A
same concentration inside membrane as outside membrane
16
Q
Hypertonic solution
A
Higher concentration outside membrane than inside membrane
17
Q
Hypotonic solution
A
Solution outside membrane has lower concentration than inside membrane
18
Q
Capillary wall is made up of
A
Thin membrane of endothelial cells
19
Q
How do substances go through capillary walls ?
A
- Junctions between endothelial cells
- vesicular transport
- Diffusion
- Filtration
20
Q
The rate of filtration at any point depends of forces called
A
Starling forces
21
Q
J[v]
A
Net fluid flux
22
Q
K[f]
A
Filtration coefficient
23
Q
P[c]
A
Capillary pressure
24
Q
P[I]
A
interstitial pressure
25
sigma
reflection coefficient
26
pi[c]
capillary oncotic pressure
27
pi[I]
interstitial oncotic pressure
28
Colloids
large molecules that are not freely permeable to the membrane
29
Colloids are more present in ____ than in interstitium
vascular fluid
30
Most prominent vascular colloid
albumin
31
hypoproteinemia
Low levels of vascular colloids
32
What does hypoproteinemia cause?
edema
33
What can changes in sodium concentration cause?
edema
34
Osmolality mostly measures
extracellular sodium concentration
35
hyponatremia causes cellular
edema
36
hypernatremia causes cellular
dehydration
37
Tonicity
term used to describe the in-vivo osmolality of a fluid; the manner in which the infused fluid will effect transcellular fluid flux.
38
T/F; the kidney can generate new nephrons
F
39
Strongest diuretic
Loop
40
Loop diuretic ADRs
OHH DAANG
1. ototoxicity (ears)
2. hypokalemia
3. hypomagnesemia
4. Dehydration
5. Allergy
6. Alkalosis
7. Nephritis
8. Gout
41
Loops lose/gain Ca
lose
42
Loop diuretic mechanism
Inhibit Na/K/Cl transport system of THICK ASCENDING LoH
43
What inhibits loops?
NSAIDs
44
When do you use loop diuretics?
edematous states, hypertension, hypercalcemia
45
Ethacrynic acid drug type
loop diuretic
46
ethacrynic MoA
similar to other loops (furosemide) but MORE ototoxicity
47
Thiazide diuretics MoA
Inhibits NaCl reabsorption in early DISTAL CONVOLUTED TUBULE, dilates capacity of nephron, decreased Ca excretion
48
When would you use a thiazide?
Hypertension, hypercalciuria, osteoporosis, diabetes insipidus
49
Thiazide ADRs
HyperGLUC
1. Hyperglycemia
2. Hyperlipidemia
3. Hyperuricemia
4. Hypercalcemia
50
K sparing diuretics MoA
Inhibit Na channel in cortical collecting duct either directly or by interfering with aldosterone
51
K sparing diuretics that directly inhibit Na channel in cortical collecting duct
triamterene and amiloride
52
K sparing diuretics that interfere with aldosterone
Spirinolactone and eplerenone
53
Diuretic's efficacy in edema therapy depends on
Amount of filtered Na normally reabsorbed at its site of action, distal to its site of action, adequate drug delivery to site of action, amount of Na that reaches site of action
54
When are diuretics appropriate?
When reduced water and sodium intake are ineffective
55
All diuretics act by reducing Na uptake in the
renal tubules; just differ in place within the tubules
56
FeNa
Fractional excretion of Na
57
Which are more powerful;
| Loop>/
Loop > K-sparing/thiazides
58
The effectiveness of thiazides and loop diuretics is dependent on
Drug concentrations in tubular lumen
59
How do thiazides and loop diuretics reach the tubular lumen?
active transport via proximal tubular cells
60
Spirinolactone gains access to ____ via _____ in the ____
Spirinolactone gains access to mineralocorticoid receptors in the cortical collecting duct through diffusion from the systemic circulation
61
natriuresis
excretion of Na in urine
62
To achieve natriuresis, what must occur?
threshold of loop or thiazide diuretic concentration ("ceiling dose")
63
Ceiling dose for furosemide
40 mg IV
64
If a patient has chronic kidney disease, is their ceiling dose reduced or increased?
reduced, because renal absorption is reduced according to decrease in GFR
65
Primary driving force for GFR
hydrostatic pressure gradient across the glomerular capillary wall
66
Myogenic reflex
Acute changes in renal perfusion pressure evoke reflex constriction or dilatation of the afferent arteriole in response to increased or decreased pressure
67
TGF
changes the rate of filtration and tubular flow by reflex vasoconstriction or dilatation of the afferent arteriole. TGF is mediated by specialized cells in the thick ascending limb of the loop of Henle called the macula densa(sense solute concentrations and tubular flow rate)
68
Angiotensin II
When reduced renal blood flow, renin is released from GRANULAR cells within the wall of the AFFERENT ARTERIOLE near the MACULA DENSA in a region called the JUXTAGLOMERULAR APPARATUS. ATII evokes vasoconstriction of the EFFERENT ARTERIOLE, and the resulting increased glomerular hydrostatic pressure elevates GFR to normal levels
69
mGFR
Measured GFR; used to determine kidney damage
70
ideal filtration marker is defined as
a solute that is freely filtered at the glomerulus, nontoxic, neither secreted nor reabsorbed by the kidney tubules, and not changed during its excretion by the kidney
71
Inulin
fructose polysaccharide with molecular wgt– 5.2 kD
| Freely filtered through glomerulus - gold standard for measuring GFR, but test is invasive
72
Methods to measure GFR:
1. CrCl
2. Cockcroft-Gault
3. Modification of diet in renal disease (MDRD)
4. Chronic kidney disease epidemiology collaboration
All based on creatinine
73
Normal range for CrCl
Adults 0.6-1.2mg/dL
74
CrCl equation
[(140-(age)) x lean body weight (kg) ] / (serumCr x 72)
^ x 0.85 if woman
75
With kidney disease, CrCl should be adjusted to
BSA (body surface area)
76
Using the Cockcroft-Gault equation with creatinine values measured by most laboratories in the United States today will result in a
10-40% overestimate
77
BUN
Blood urea nitrogen - concentration of nitrogen (in urea) in serum (NOT RBCs)
78
Normal BUN
8 –23 mg dL
79
Elevated BUN indicates
Higher production (high protein diet), less tubular reabsorption,
80
Azotemia
clinical condition of elevated BUN (READ TABLE 11-1 in Chapter 11 of the Handbook of Laboratory Values to see causes of azotemia according to broad classification of pre-renal, intra-renal, or post-renal azotemia).
81
BUN/serum creatinine ration (normal)
10-15:1. Greater than 20:1 in renal disease
