Block 4 Exam Flashcards
1
Q
BUN equation
A
Plasma osmolality = 2[Na+] + glucose/18 + BUN/2.8
2
Q
Capillary filtration equation
A
Kf[(Pc - Pi) - sigma( Pi(c) - Pi(i))]
3
Q
Kf
A
Filtration coefficient
4
Q
Pc
A
Capillary hydrostatic pressure
5
Q
Pi
A
Interstitial hydrostatic pressure
6
Q
Pi(c)
A
Capillary oncotic pressure
7
Q
Pi(i)
A
Interstitial oncotic pressure
8
Q
Sigma
A
Protein reflection coefficient
9
Q
Primary functions of the kidneys
A
Filtration
Reabsorption
Secretion
10
Q
Afferent arteriole resistance
A
high
11
Q
Glomerular capillaries resistance
A
low
12
Q
Efferent arteriole resistance
A
high
13
Q
Vasa Recta resistance
A
low
14
Q
Vasa recta capillaries resistance
A
low
15
Q
Renal veins resistance
A
low
16
Q
Afferent arteriole pressure
A
high
17
Q
Glomerular capillaries pressure
A
high
18
Q
Efferent arterioles pressure
A
high
19
Q
Vasa recta pressure
A
low
20
Q
Vasa recta capillaries pressure
A
low
21
Q
Renal veins pressure
A
low
22
Q
Leaky epithelia electrical resistance
A
low
23
Q
Leaky epithelia transport rate
A
high
24
Q
Leaky epithelia chemical gradient
A
low
25
Leaky epithelia transepithelial voltage
low
26
Leaky epithelia tight junction structure/selectivity
limited
27
Leaky epithelia membrane infolding
extensive
28
Leaky epithelia mitochondria
a lot
29
Tight epithelia electrical resistance
high
30
Tight epithelia transport rate
low
31
Tight epithelia chemical gradient
high
32
Tight epithelia transepithelial voltage
high
33
Tight epithelia tight junction structure/selectivity
extensive
34
Tight epithelia membrane infolding
Limited
35
Tight epithelia mitochondria
fewer
36
Proximal tubule Na+ reabsorption
60-70% of filtered Na+
37
Proximal tubule Water reabsorption
60-70% of filtered water
38
Proximal tubule sugar reabsorption
All of the glucose and most other sugars
39
Proximal tubule Protein reabsorption
Nearly all amino acids, peptides and protein by secreting proteases
40
Proximal tubule Phosphate and sulfate reabsorption
Nearly all of both
41
Proximal tubule organic cations and anions reabsorption
reabsorps
42
Proximal tubule HCO3 - reabsorption
80-90% of filtered HCO3 -
43
Proximal tubule Ca2+ and Mg2+ reabsorption
50% of filtered
44
Proximal tubule Cl- reabsorption
50% of Cl-
45
Proximal tubule secretions
Toxins
| Ammonium
46
What does the proximal tubule synthesize
Glucose
47
Proximal tubule apical membrane in-foldings
extensive
48
Proximal tubule basolateral membrane in-foldings
Extensive
49
Proximal tubule nucleus
Large
50
Proximal tubule mitochondria
Numerous located to basolateral in-foldings
51
S1 location
Renal cortex
| Lumen negative
52
S2 location
Medullary ray
| Lumen negative
53
S3 location
Outer medullae
| Lumen Positive
54
What does the loop of Henle include?
S3 segments of proximal tubules
Thin descending limbs
Thin ascending limbs
Thick ascending limbs
55
Thin descending limb cells
Thin
56
Thin descending limb mitochondria
Few
57
Thin descending limb membrane in-foldings
None
58
Thin ascending limbs location
Deep nephrons only
59
Thin ascending limb cells
Thin
60
Thin ascending limb mitochondria
few
61
Thin ascending limb membrane in-foldings
None
62
What does the Thick ascending limb reabsorb
```
20-30% of NaCl
K+
Ca2+
Mg 2+
HCO3 -
```
63
What does thick ascending limb secrete
Tamm-Horsfall protein
64
Tamm-Horsfall protein
Plays a role in immunity and stone prevention
65
Another name for thick ascending limb
Diluting segment
66
Thick ascending limb mitochondria
Lots
67
Thick ascending limb apical membrane in-foldings
Modest
68
Thick ascending limb basolateral in-foldings
Lots
69
Macula densa nuclei
Large
70
Macula densa mitochondria
lots
71
Distal convoluted tubule divisions
Early of Classical DCT
| Late or not really the DCT DCt
72
How much NaCl does the classical DCT reabsorb?
5-10%
73
What does the Early DCT reabsorb?
NaCl
Ca2+
K+ sometimes
74
What does the early DCT secrete?
K+ sometimes
75
How much NaCl does the late DCT reabsorb?
5-10%
76
What does the late DCT reabsorb?
NaCl
| K+ sometimes
77
What does the late DCT secrete?
K+ sometimes
78
DCT apical membrane in-foldings
Some
79
DCT mitochondria
Numerous
80
DCT basolateral membrane in-foldings
Intermediate amount
81
Collecting ducts cells
Principal cell
Alpha intercalated cel
Beta intercalated cell
82
Inner medullary collecting ducts mitochondria
Few
83
Inner medullary collecting ducts membrane in-foldings
None
84
Inner medullary collecting ducts tight junctions
Tightest of any segment
85
Inner medullary collecting ducts gradients
large
86
Inner medullary collecting ducts Na+ transport rates
Low rates
87
Inner medullary collecting ducts other transport
High rates of urea, ammonia, and water
88
Renal clearance
Volume of plasma totally cleared of a substance in a given time
89
GFR in healthy individuals
Greater than 90mL/min/1.73m^2
90
Use eGFR to assess renal function in:
Chronic Kidney Disease (CKD)
91
Serum creatinine must be used to assess renal function in
Acute Kidney Injury (AKI)
92
Albuminuria
Pathological condition wherein the protein albumin is abnormally present in the urine
93
24-hour urine collection Albuminuria
>30 mg albumin/24 hours
94
Spot collection Albuminuria
Urine albumin/creatine > 30 mg/g
95
Heamturia
Presence of red blood cells in urine
96
Hemoglobinuria
Presence of hemoglobin in the urine
97
Dysmorphic erythrocyte means
Damage to glomeruli
98
CKD Stage 1 GFR
Greater than or equal to 90
99
CKD Stage 2 GFR
60-89
100
CKD Stage 3a GFR
45-59
101
CKD Stage 3b GFR
30-44
102
CKD Stage 4 GFR
15-29
103
CKD Stage 5 GFR
Less than 15
104
CKD Primary risk factors
Diabetes
| Hypertension
105
CKD Other risk factors
```
Family history of CKD
Advancing age
Systemic infections
Loss of kidney mass
Autoimmune disease
```
106
Acute Kidney Injury (AKI)
Rapid deterioration of kidney function manifested by an increase in SrCf > 0.3 mg/dl < 48 hr OR increase in SrCr > 50% in < 48 hr
107
Patients who develop AKI may experience:
Complete recovery of renal function
Development of progressive chronic kidney disease (CKD)
Exacerbation of the rate of progression of preexisting CKD
Irreversible loss of kidney function and evolve into ESRD
108
Normal kidney size
10-12 cm
109
Kidney size in AKI
Normal or hydronephrotic
110
Kidney size in CKD
Reduced
111
Causes of prerenal AKI
Decreased ECV
Renal vasoconstriction
Large vessel disease
112
Causes of Acute tubular necrosis (ATN)
Ischemic progression of prerenal AKI
Nephrotoxins
Contrast media
113
Causes of Acute interstitial nephritis (AIN)
Allergic reactions
Infection
Infiltrative
Autoimmune
114
Causes of ureteral AKI
Stone
Neoplasms or tumors
Severe constipation
115
Causes of bladder neck AKI
BPH
Prostate cancer
Neurogenic bladder
116
Postrenal AKI
Ureteral
| Bladder neck
117
Intrinsic (renal) AKI
Acute tubular necrosis (ATN)
Acute interstitial nephritis (AIN)
Glomerulonephritis
118
Prerenal AKI diagnosis
FENa <1.0%
BUN/Cr > 20:1
Bland sediment
+/- Hyaline casts
119
Acute tubular necrosis (ATN) diagnosis
FENa > 2.0%
BUN/Cr < 20:1
Muddy brown casts
+/- RBCs
120
Acute interstitial nephritis (AIN) diagnosis
WBC casts
WBCs
+/- RBCs
121
Glomerulonephritis diagnosis
Dysmorphic RBCs
| RBC casts
122
Postrenal AKI diagnosis
Bland sediment
+/- nondysmorphic RBCs
+/- hydronephrosis by US
123
Azotemia
A build-up of nitrogenous waste in blood (BUN and SrCr)
124
Uremia
A constellation of symptoms and signs of multiple-organ dysfunction caused by retention of "uremic toxins"
125
Kidney transplant
Best option for renal replacement therapy
126
Three year mortality in ESRD
~50%
127
Renal Hemodynamics
Volume of plasma filtered/unit time
128
Renal Plasma Flow (RPF)
Rate of plasma flowing through the vasculature (~400-600 mL/min) or 600-900 L/day
129
Glomerular filtration
Filtration of plasma & non-protein constituents into Bowman's space
130
Ultrafiltration
Leaves proteins and RBCs in blood because they cannot pass through the selective glomerular filtration barrier
131
Glomerular filtration rate
Rate of fluid movement from capillary space into Bowman's space
132
Molecules to measure GFR criteria
Substance must be freely filterable in glomeruli
Substance must be neither reabsorbed nor secreted by the tubules
Substance must not be synthesized, broken down or accumulated by the kidney
Physiologically inert
133
Physiologically inert
Not toxic and without effect on renal function
134
GFR equation
GFR = Ux*V/Px
135
Amount of inulin filtered
P(in) * GFR
136
Amount of inulin excreted in the urine
U(in) * V
| Same as amount filtered
137
Metabolism of creatine phosphate in men
20 to 25 mg/kg/day
138
Metabolism of creatine phosphate in women
15 to 20 mg/kg/day
139
Filtration barrier components
Slit diaphragm
Basement membrane
Fenestrated endothelium
140
GFR influenced by:
Blood pressure and blood flow
Obstruction to urine outflow
Loss of protein-free fluid
Hormonal regulation
141
Hormonal regulation
Renin-angiotensin
Aldosterone
ADH
ANP
142
P(gc)
Glomerular capillary hydrostatic pressure
143
Pi(bs)
Bowman's space oncotic pressure
144
P(bs)
Bowman's space hydrostatic pressure
145
Pi(gc)
Glomerular capillary oncotic pressure
146
Renal plasma flow equation
RPF = (1-Hct)*RBF
147
Normal Renal plasma flow
600 mL/min given a hematocrit of 40%
148
Filtration fraction equation
FF = GFR/RPF
149
Filtration fraction
Volume of filtrate that forms from a given volume of plasma entering the glomeruli
150
Increase AA resistance
```
Decrease P(gc)
Decrease RBF
```
151
Increase EA resistance
```
Increase P(gc)
Decrease RBF
```
152
Increase AA and EA resistance
```
Decrease RBF
Unchanged P(gc)
```
153
Diabetes
Fasting blood glucose > 126mg/dl
Random glucose >200 mg/dl
HbA1c > 7.0%
154
Type 1 Diabetes (juvenile onset)
Complete loss of insulin production
| Likely due to inflammatory/immune-mediated insult
155
Type 2 diabetes (adult onset)
Initial insulin resistance
| Eventual beta-cell failure and decreased insulin secretion
156
Low glomerular filtration rate
Generally GFR < 60 mL/min
157
Albuminuria or proteinuria
Detectable at 1+ or 30 mg/dl on dipstick
| Measured in urine @ >30 mg albumin or 300 mg protein per 24 hrs
158
Clinical risk factors of DKD
```
Race/genetics
Gender
Obesity
Poor glycemic control
Hypertension
Other diabetic microvascular end organ complications
```
159
Hemodynamic
Intraglomerular hypertension/hyperfiltration
160
Hyperglycemia
Advanced glycation end products
| Increased flux through polyol and hexosamine pathways
161
Growth Factors and Cytokines Associated with DKD
```
Angiotensin II
Transforming Growth Factor-beta
Endothelin
Platelet-Derived Growth Factor
Insulin-like Growth Factor
Tumor Necrosis Factor
Interleukin-1
```
162
Reactive Oxygen Species Enzymatic
Catalyzed by NADPH oxidase
163
Reactive Oxygen Species Non-enzymatic
Leakage from mitochondrial electron transport chain
164
Mechanisms targeted by current treatments
Glucose
Blood pressure
SGLT2
165
Glucose targets
Goal of Hgb A1c ~7.0%
166
Blood pressure with T2DM
130/80-85 is just right
167
60% of TBW
Intracellular Fluid
168
40% of TBW
Extracellular Fluid
169
20% of ECF
Plasma
170
Plasma
Noncellular, protein rich fluid
171
Is Na permeable to plasma membranes?
No (unless using facilitated diffusion, secondary active transport, or primary active transport)
172
Does Na+ contribute to tonicity?
Yes, because it is an effective osmolyte
173
What is tonicity
The concentration of effective osmolytes. They cause water shifts from one compartment to another assuming water is permeable across the membrane that separates those compartments
174
Does Na+ contribute to the ECF osmolality
Yes
175
Does urea cross plasma membranes
Yes
176
Does urea contribute to plasma osmolality
Yes
177
Importance of filtration
Need to remove metabolic waste and toxins
178
Importance of reabsorption
Maintains plasma Na+ concentrations
Maintains water balance
Regulates plasma pH
Regulates balance of other solutes
179
Importance of secretion
Removes toxins
| H+, K+ and more
180
Hilus
Renal artery and nerves enter here
| Renal vein, lymphatics, and ureter exit here
181
Cortex
Outer layer
182
Medulla
Inner layer
Striated due to renal pyramids
Can be highly concentrated, even if plasma is very dilute
183
Glomerular Filtration Barrier
```
Glycocalyx
Endothelial cells of glomerular capillaries
Basement membrane
Slit diaphragm
Podocytes
```
184
Basement membrane
Lamina rara interna
Lamina densa
Lamina rara externa
185
Claudins
Arranged like pearls on a string
Strands are NOT continuous
Direct relationship between selectivity/resistance and # of strands
186
Thin Descending Limb Reabsorption
5% filtered water
187
NKCC2 in Thick ascending limb is inhibited by what
Loop diuretics
188
Macula densa functions
Sense luminal NaCl as part of tubuloglomerular feedback
Regulate renin release from juxtaglomerular cells
Release paracrine factors that regulate afferent and efferent arteriolar tone
189
What increases NaCl reabsorption in the DCT
Aldosterone
190
What causes the DCT to reabsorb water
ADH/vasopressin
191
DCT Transport rates
Moderately low
192
DCT transepithelial voltages
Moderate
193
Collecting Duct Reabsorbtion
0-5% filtered NaCl
194
What does ADH cause the collecting duct to reabsorb
Urea
| Water
195
What causes an increase in Na+ reabsorption in the collecting duct
Aldosterone
196
What causes a decrease in Na+ reabsorption in the collecting duct?
NO
Endothelin
Bradykinin
ANF
197
Collecting duct Secretion
K+
H+
NH4 +
198
What causes an increase in K+ secretion in the collecting duct
Aldosterone
199
What inhibits the ENaC channel in the collecting duct?
Amiloride
200
Collecting duct Membrane in-foldings
Limited
201
Collecting Duct mitochondria
Some
202
Collecting duct transport rate
low
203
collecting duct transepithelial voltage
high
204
Collecting duct transepithelial resistance
moderately high
205
Detrusor muscle inhibition of NE release
Contraction
206
Internal sphincter inhibition of NE release
Relaxation
207
P(uf) > 0
Filtration
208
P(uf) <0
Reabsorption
209
Permselectivity
Ratio of Ufx/Px
210
Clearance ratio
How well the kidney clears solute X from the blood compared to inulin (completely cleared)
211
Clearance ratio = 0
Solute is not freely filtered or excreted
212
Clearance ratio > 1
NET secretion of substance X along nephron
213
Clearance ratio < 1
NET reabsorption of substance X along nephron
214
Maintaining GFR
Maintaining stable and optimal extracellular levels of solutes and water (maintains homeostasis)
215
Normal GFR
125 mL/min
216
Peritubular capillaries originate from
Efferent arterioles of superficial/cortical glomeruli
217
Vasa recta originate from
Efferent arterioles of juxtamedullary glomeruli
218
2 main functions of peritubular capillaries
Deliver oxygen and nutrients to epithelial cells
| Reabsorption of fluid and solutes from interstitium
219
Cells of the Juxtaglomerular apparatus
Mesangial cells
Macula densa cells
Granular cells
220
Mesangial cells
Secrete the extracellular matrix
221
Macula densa cells
Specialized epithelial cells
Located at transition between TAL and distal tubule
Basolateral aspects are in contact with mesangial cells of glomerulus, afferent and efferent arterioles
222
Granular cells
Located in the wall of AA
| Specialized smooth-muscle cells that produce, store, and release renin
223
JGA
Helps regulate blood flow and filtration rate, modulate Na+ balance and systemic BP
224
Apical & Basolateral infoldings
Increased surface area to accommodate more transporters on that membrane
225
More mitochondria
High need for ATP
226
Proximal Tubule Na+ Transport Primary mechanism
Na+/H+ exchange (apical)
Na+/K+ ATPase (basolateral)
Na+/HCO3 - (basolateral)
227
S1/S2 Na+ Transport
Na+ and H+ gradients favor H+ efflux and Na+ influx
228
S3 Na+ transport
NHE makes up majority of Na+ reabsorption
229
Proximal tubule Solvent drag Na+ reabsorption
30% of NaCl reabsorption in PT
230
Proximal Tubule Cl- Transport S1/S2
Solvent drag
| Electrochemical gradient
231
Proximal tubule Cl- reabsorption Solvent drag
```
Na/HCO3 cotransporter (basolateral)
creates osmotic gradient
drives water reabsorption
Lumen - voltage
Chloride reabsorbed paracellularly
```
232
Cl- reabsorption S3
```
Cl-/HCO3 anion exchange (apical)
KCl cotransporter (basolateral)
Paracellular reabsorption
```
233
NaCl Transport Early TAL
Na+ reabsorbed passively
NKCC2 (apical)
Na+/K+ ATPase (basolateral)
234
NaCl Transport Late TAL
Na+ can be passively secreted
NKCC2 (apical)
Na+/K+ ATPase (basolateral)
235
Chloride Transport in Thick ascending limb
NKCC2 (apical)
KCl cotransporter (basolateral)
Cl- channel (basolateral)
Paracellular transport
236
Classical or Early DCT NaCl Transport
NCC (Apical)
KCC (basolateral)
Cl- channel (basolateral)
Na/K ATPase (basolateral)
237
What inhibits NCC in the Classical DCT
Thiazide diuretics
238
Late or not really the DCT DCT NaCl Transport
```
NCC (apical)
ENaC (apical)
Na/K ATPase (basolateral)
KCC (basolateral)
Cl- channel (basolateral)
```
239
What inhibits ENaC in the late DCT
Amiloride diuretics
240
Paracellular transport in DCT
Cl- ions due to lumen negative charge
241
Collecting Duct Principal Cell Transport of Na+
ENaC (apical)
| Na/K pump (basolateral)
242
Collecting Duct Principal cell Transport of Cl-
Paracellular driven by lumen negative voltage
243
Collecting Duct Beta Intercalated Cell Cl- Transport
```
Transcellular
Anion exchange (Apical)
Cl- channel (basolateral)
```
244
Inner medullary collecting ducts Na+ Reabsorption
ENaC (apical)
CGGC (apical)
NBC (Apical)
Na/K pump (basolateral)
245
Inner medullary collecting ducts Na+ Secretion
Paracellular driven by electrochemical gradient
246
Inner medullary collecting duct Cl- Reabsorption
```
Anion Exchange (apical)
Cl- channel (basolateral)
Paracellular
```
247
Inner medullary collecting duct Cl- Secretion
NKCC1 (basolateral)
| CFTR (apical)
248
Components of glomerulus
Endothelial cells
Mesangial cells
Glomerular epithelial cells (podocytes)
249
ESRD pathology
Tubular atrophy and interstitial fibrosis
250
Glomerular cap pathology
Expansion of mesangial matrix
Kimmelstiel-Wilson lesions
Arteriolar hyalinosis
251
Expansion of the mesangial matrix
Cytokines and growth factors => profibrotic
252
Kimmelstiel-Wilson lesions
Increases in mesangial matrix from damage as a result of glycation of proteins
253
Podocyte pathology
Thickened basement membrane
| Disrupted foot processes
254
DKD progression
Hyperfiltration
Microalbuminuria
Macroalbuminuria
Increasing albuminuria
255
Hyperfiltration
GFR increases
256
Macroalbuminuria
Nephrotic syndrome
| >3.5g/day of albumin being excreted in urine
257
Increasing albuminuria
Decrease in GFR
258
FATP2
Expressed in luminal membrane of PT and takes up fatty acids
259
Progression of Renal Insufficiency
HTN => Increase PTH => Anemia => Increase Phosphorus => Acidosis, hyperkalemia => Uremic syndrome
260
Consequences of AKI
Accumulation of nitrogenous wastes
Disturbances in fluids/electrolytes
Acid-base disorders
261
Anuria
Less than 50mL of urine output in 24 hours
262
Drugs Targeting RAAS
ACE inhibitors
ARBs
Renin inhibitors
263
Renin Target
Cortical collecting duct
264
Effect of renin on CCD
Increased cAMP and PKA
265
Low end of [ANGII] effect
Maintain GFR because efferent arterioles will constrict more than afferent arterioles
266
High end of [ANGII] effect
GFR will fall because of too much constriction of both afferent and efferent arterioles
267
ANGII effect on PT
Stimulates or inhibits Na+ reabsorption
268
ANGII effect binding AT1R on THAL
Stimulates Na+ reabsorption via NKCC2
269
ANGII effect binding AT2R in THAL
Inhibits Na+ reabsorption via NKCC2
270
ANGII effect on DCT
Stimulates NaCl reabsorption by increasing apical NCCs & increasing phosphorylation of NCCs
271
ANGII effect on CD
Increases Na+ reabsorption via ENaC
272
ANGII effect on Adrenal cortex
Stimulates aldosterone release
273
ANGII effect on Granular cells
Inhibits release of renin
274
ANGII effect on vasculature
Vasoconstriction
275
ANGII effect on OVLT & SFO
Stimulates thirst & AVP release
276
Aldosterone effect on DCT
Stimulates NaCl reabsorption via NCC
277
Aldosterone effect on CD
Stimulates Na+ reabsorption & K+ secretion
278
Low levels of RSN activation
Sodium reabsorption
279
Medium levels of RSN activation
Renin release
280
High levels of RSN activation
Increased renal vascular resistance
281
RSNA effect on PT
Increases Na+ transport
282
RSNA effect on THAL
Increases or decreases Na+ transport
283
RSNA effect on collecting duct
Complicated
284
RSNA effect on JGA granular cells
Increases prorenin release
285
RSNA effect on OVLT & SFO
Stimulates thirst centers and release of AVP
286
ANP/BNP effect on vasculature
Vasodilation
287
ANP/BNP effect on JGA granular cells
Decrease prorenin release
288
ANP/BNP effect on PT
Decreases Na+ reabsorption
289
ANP/BNP effect on THAL
Decreases Na+ reabsorption
290
ANP/BNP effect on Macula densa
Decreased Na+ reabsorption and TGF
291
ANP/BNP effect on CCD
Decreased Na+ reabsorption
292
ANP/BNP effect on IMCD
Decreased Na+ reabsorption
293
High [ET-1] effect on PT
Inhibits NHE3 leading to decreased Na+ reabsorption
294
Low [ET-1] effect on PT
Increase PKC leading to increased Na+ reabsorption
295
Endothelin effect on THAL
Decreases Na+ reabsorption
296
Endothelin effect on CD
Decreases Na+ reabsorption
297
Nitric oxide effect on PT
Inhibits Na+ reabsorption
298
Nitric oxide effect on TAL
Inhibits Na+ reabsorption
299
Nitric oxide effect on CD
Inhibits Na+ reabsorption
300
Cadmium
Causes Fanconi Syndrome
PT damage
Inhibits Na/K ATPase
Inhibits SGLTs and NaPis in PT
301
Fanconi syndrome
Loss of PT function
Decreased GFR
Increased urinary flow rate
Excessive loss of major ions
