1
Q
What is the typical adult human kidney mass weight and dimensions
A
approximately 150 g 12.5 cm length 6 cm width 2.5 cm depth
2
Q
What are the basic functional units of the kidney responsible for filtration and urine formation
A
nephrons
3
Q
What percentage of nephrons are located primarily in the kidney cortex for waste removal and nutrient reabsorption
A
85% cortical nephrons
4
Q
What nephron type has loops of henle extending deep into kidney medulla for urine concentration
A
juxtamedullary nephrons
5
Q
What are the three main components of kidney excretory function
A
glomerular filtration tubular reabsorption and tubular secretion
6
Q
What kidney function maintains body fluid volume and osmolarity
A
regulation of water balance
7
Q
What kidney process controls blood ph through bicarbonate and hydrogen ion handling
A
regulation of acid base balance
8
Q
What kidney ions are primarily regulated for neuromuscular and cellular function
A
electrolytes sodium potassium calcium
9
Q
What kidney enzyme regulates systemic blood pressure through angiotensin activation
A
renin
10
Q
What hormone stimulates red blood cell production from kidney peritubular cells
A
erythropoietin epo
11
Q
What kidney function helps maintain core body temperature
A
regulation of body temperature
12
Q
What major artery supplies oxygenated blood to both kidneys
A
renal artery
13
Q
What percentage of cardiac output receives the human kidneys continuously
A
approximately 20-25%
14
Q
What is total renal blood flow volume in normal adults
A
approximately 1 L/min
15
Q
What laboratory parameter estimates effective renal plasma flow
A
para aminohippuric acid pah clearance
16
Q
What kidney region receives highest blood flow for filtration function
A
renal cortex
17
Q
What vascular structure surrounds cortical nephrons for reabsorption
A
peritubular capillaries
18
Q
What vascular structure surrounds juxtamedullary nephrons in medulla
A
vasa recta
19
Q
What is the primary site of glomerular filtration in nephron
A
glomerulus bowmans capsule
20
Q
What hydrostatic pressure drives glomerular filtration averaging 55 mm Hg
A
glomerular capillary hydrostatic pressure
21
Q
What bowmans space pressure opposes glomerular filtration at 15 mm Hg
A
bowmans capsule hydrostatic pressure
22
Q
What plasma protein oncotic pressure opposes filtration at 30 mm Hg
A
colloid oncotic pressure
23
Q
What is net filtration pressure favoring ultrafiltrate formation in bowmans space
A
10 mm Hg
24
Q
What arteriole brings blood into glomerular capillaries
A
afferent arteriole
25
What arteriole carries blood out of glomerular capillaries
efferent arteriole
26
What sequence describes blood flow through nephron vasculature
renal artery afferent arteriole glomerulus efferent arteriole peritubular capillaries vasa recta renal vein
27
What sequence describes filtrate flow through nephron to final urine
glomerulus bowmans space proximal convoluted tubule descending limb loop of henle ascending limb distal convoluted tubule collecting ducts renal calyces ureter bladder urethra
28
What kidney structure collects urine from multiple papillae
renal pelvis
29
What urine collecting funnels connect papillae to renal pelvis
minor calyces
30
What structure within bowmans capsule functions as non selective plasma filter
glomerular capillary tuft sieve
31
What is the measured specific gravity of glomerular ultrafiltrate
1.01
32
What fraction of renal plasma flow forms glomerular ultrafiltrate per minute
one fifth or 120 mL/min
33
What is the typical protein concentration in normal glomerular ultrafiltrate
about 10 mg/dL low molecular weight proteins
34
Name the three cellular layers plasma filtrate passes through in glomerular filtration
capillary endothelial wall basement membrane and visceral podocyte epithelium
35
What fenestrated layer forms first barrier in glomerular filtration
capillary wall membrane
36
What intertwining epithelial cell processes form filtration slits
podocytes foot processes
37
What charge barrier repels negatively charged plasma proteins like albumin
shield of negativity glycocalyx
38
What vascular pole structure maintains glomerular capillary hydrostatic pressure
juxtaglomerular apparatus
39
What enzyme secretes from juxtaglomerular cells in afferent arteriole regulating blood pressure
renin
40
What dct cell type senses blood pressure changes in juxtaglomerular apparatus
macula densa
41
What vascular response occurs to low blood pressure via juxtaglomerular apparatus
afferent arteriole dilation efferent constriction
42
What vascular response occurs to high blood pressure via juxtaglomerular apparatus
afferent constriction efferent dilation
43
What plasma protein serves as substrate for renin enzyme in raas
angiotensinogen
44
What inactive decapeptide forms from renin cleavage of angiotensinogen
angiotensin i
45
What active octapeptide vasoconstrictor forms from ace cleavage of angiotensin i
angiotensin ii
46
Where does angiotensin converting enzyme ace primarily convert angiotensin i to ii
lung endothelium
47
What three main raas effects conserve sodium and water raising blood pressure
vasodilation proximal sodium reabsorption aldosterone and adh release
48
What pct process increases with angiotensin ii stimulation
sodium reabsorption
49
What adrenal cortex hormone causes distal tubule sodium retention potassium excretion
aldosterone
50
What hypothalamic hormone stimulates collecting duct water reabsorption
antidiuretic hormone adh
51
What raas stimulus activates juxtaglomerular renin release
decreased blood pressure low plasma sodium
52
What clearance test provides most accurate measure of glomerular filtration rate without tubular reabsorption or secretion
inulin clearance test
53
What is the chemical composition of inulin used for gold standard gfr measurement
fructose polymer
54
How is inulin administered for clearance testing
continuous iv infusion at constant rate
55
What muscle metabolism waste product is used in most common clinical gfr clearance test
creatinine
56
What enzyme produces creatinine from creatine during muscle metabolism
creatine phosphokinase
57
Name three alternative gfr markers besides creatinine and inulin
cystatin c beta 2 microglobulin radioisotopes
58
What is the disadvantage of urea clearance as gfr test
40% tubular reabsorption
59
What is the formula for creatinine clearance calculation
urine creatinine x volume/24h x 1.73/plasma creatinine
60
What specimen timing creates greatest error in creatinine clearance testing
improperly timed 24-hour urine collection
61
What plasma creatinine collection timing optimizes 24-hour urine clearance accuracy
midpoint of urine collection period
62
What storage condition prevents creatinine degradation during 24-hour urine collection
refrigerated throughout collection and storage
63
What minimum blood volume is required for serum creatinine in clearance testing
1 mL minimum 0.5 mL
64
What patient hydration improves 24-hour urine collection accuracy
drink at least 8 cups liquid on collection day
65
What tubular process causes creatinine overestimation of gfr
tubular secretion increases with high blood levels
66
Which antibiotics inhibit creatinine tubular secretion causing falsely low serum levels
gentamicin cephalosporins cimetidine
67
What bacterial action degrades urinary creatinine at room temperature
bacterial breakdown
68
What dietary factor falsely elevates creatinine clearance results
heavy meat diet before plasma collection
69
What patient groups show unreliable creatinine clearance due to muscle mass variation
athletes heavy exercisers muscle disease patients
70
Which antibiotic combination elevates serum creatinine by 0.4-0.5 mg/dL
trimethoprim sulfamethoxazole
71
What patient factors affect creatinine production rate
sex and race due to muscle mass differences
72
What low molecular weight protein produces constantly by all nucleated cells for gfr estimation
cystatin c mw 13
73
How does plasma cystatin c concentration relate to gfr
inversely proportional increased cystatin c = decreased gfr
74
What makes cystatin c superior to creatinine for gfr monitoring
production unaffected by muscle mass sex or race
75
What protein dissociates constantly from mhc class i for tubular function assessment
beta 2 microglobulin
76
What is the most frequently used egfr calculation formula in clinical practice
mdrd modification of diet in renal disease
77
What four parameters does original mdrd formula include
serum creatinine age sex ethnicity
78
What is the idms traceable mdrd formula constant multiplier
175
79
What mdrd formula gender correction factor applies to females
x 0.742
80
What mdrd formula ethnicity correction factor applies to black patients
x 1.212 or 1.202
81
What six parameter mdrd formula adds bun and albumin
based ss bun age serum creatinine ethnicity serum albumin sex
82
What three parameter cockcroft gault formula parameters
body weight age sex serum creatinine
83
What is the cockcroft gault creatinine clearance formula
(140-age) x weight x 0.85 if female/72 x scr
84
What newer egfr formula uses minimum scr/k ratio and alpha correction
ckd epi chronic kidney disease epidemiology collaboration
85
What percentage of glomerular filtrate volume is normally reabsorbed by renal tubules
0.99
86
What renal function loss occurs earliest in disease processes
tubular reabsorption and secretion
87
What percentage of urine volume is water versus solutes
95% water 5% solutes
88
What is the approximate total daily urinary solute excretion in grams
60 g with 35 g organic 25 g inorganic
89
What transport requires carrier proteins and metabolic energy across tubular cell membranes
active transport
90
What transport moves solutes down concentration gradient without energy expenditure
passive transport
91
Which nephron segment reabsorbs glucose amino acids salts and bicarbonate by active transport
proximal convoluted tubule pct
92
Which loop of henle segment reabsorbs sodium chloride actively impermeable to water
thick ascending limb
93
Which hormone controls sodium reabsorption in distal convoluted tubule and collecting duct
aldosterone raas
94
Which hormone controls water reabsorption in late distal tubule and collecting duct
antidiuretic hormone adh
95
What denotes maximal tubular reabsorption capacity per minute for filtered solutes
tm
96
What plasma concentration stops active tubular reabsorption of glucose
renal threshold 160-180 mg/dL or 350 mg/min
97
What is the renal threshold plasma concentration range for sodium reabsorption
110-130 mmol/L
98
What countercurrent multiplier mechanism creates medullary osmotic gradient
water removal descending limb salt removal ascending limb
99
What passive process moves water across semipermeable membranes down osmotic gradient
osmosis
100
What medullary structure prevents water reabsorption in ascending loop of henle
water impermeable walls
101
What hormone regulates final urine concentration in collecting ducts
adh vasopressin
102
What physiologic state increases adh secretion concentrating urine
decreased body hydration low volume
103
What physiologic state decreases adh secretion producing dilute urine
increased body hydration high volume
104
What is tubular fluid osmolality entering proximal tubule
isosmotic 300 mOsm/kg
105
What osmolality change occurs in thin descending loop of henle
becomes progressively hyperosmotic
106
What is osmolality at loop of henle u turn in medulla
maximally hyperosmotic up to 1200 mOsm/kg
107
What osmolality change occurs in thick ascending limb
becomes progressively hypo osmotic
108
What osmolality characterizes fluid exiting distal tubule before collecting duct
slightly hypo osmotic
109
What osmolality range can final urine achieve under adh control
hyperosmotic to 1200 hypoosmotic or isosmotic 300 mOsm/kg
110
What test measures particle concentration to assess renal concentrating diluting ability adh response
urine serum osmolality test
111
What normal urine to serum osmolality ratio indicates adequate renal concentrating function
1:1 to 3:1
112
What two osmometer principles measure freezing point depression or vapor pressure dew point
freezing point depression osmometer vapor pressure osmometer
113
What urine serum osmolality ratio with fluid restriction differentiates neurogenic from nephrogenic diabetes insipidus
urine osmolality below 400 mOsm urine serum 1:1
114
What urine osmolality response to adh challenge confirms neurogenic diabetes insipidus
urine osmolality rises above 800 mOsm urine serum 3:1
115
What urine osmolality response to adh challenge confirms nephrogenic diabetes insipidus
urine osmolality remains below 400 mOsm urine serum 1:1
116
What test compares day night urine volume and specific gravity for concentrating ability
specific gravity test
117
What test assesses kidney response to hydration status by comparing osmolar clearance to urine flow
free water clearance test
118
What is first formula step in free water clearance calculation
osmolar clearance = uosm x v/plasma osmolality
119
What is second formula for free water clearance ch2o
urine volume minus osmolar clearance
120
What process moves substances from peritubular capillary blood into tubular filtrate
tubular secretion
121
What are two primary functions of tubular secretion
eliminate unfiltered waste products regulate acid base balance
122
What hydrogen ion forms secreted for acid base regulation
hydrogen ions as ammonium nh4 hydrogen phosphate and weak organic acids
123
What tubular disorder causes metabolic acidosis with inability to acidify urine ph above 5.5
renal tubular acidosis
124
What blood urine ph pattern characterizes renal tubular acidosis
alkaline urine ph basic blood ph acidic
125
What pct secretes hydrogen ions ammonium weak acids bases and urea
proximal tubule
126
What thick ascending loop of henle secretes primarily
hydrogen ions nh4 and urea
127
What dct secretes potassium uric acid some drugs and hydrogen nh4
distal convoluted tubule
128
What collecting tubule secretes under aldosterone control
hydrogen nh4 and potassium some drugs
129
What obsolete dye excretion test measured tubular secretion function
phenolsulfonphthalein psp test
130
What exogenous substance clearance test most accurately measures effective renal plasma flow
para aminohippuric acid pah test
131
What plasma protein binding characteristic allows pah complete extraction measuring rpf
loosely bound to plasma proteins
132
What disadvantage limits routine clinical use of pah clearance testing
requires iv infusion exogenous substance
133
What three urine tests simultaneously assess renal acid secretory function
urine ph titratable acidity urinary ammonia
134
What patient preparation precedes 2-hour interval urine collections for acid secretion testing
oral ammonium chloride priming acid load
135
What urine preservation allows ph titratable acidity and ammonia testing
fresh or toluene preserved specimens
136
How is urinary ammonium concentration calculated from acidity measurements
total acidity minus titratable acidity
137
What urine ph above 5.5 with systemic acidosis indicates distal renal tubular acidosis type 1
impaired h+ secretion
MTAP - AUBF
flashcards
Decks in class (13)
# Cards
-
1 - INTRO STUFF AGAIN129
-
2 - RENAL FUNCTION137
-
3 - URINALYSIS INTRO291
-
4 - PHYSICAL EXAMINATION228
-
5 - CHEMICAL EXAMINATION373
-
6 - MICROSCOPIC EXAMINATION401
-
7 - RENAL DISORDERS177
-
8 - SYNOVIAL FLUID AND SEROUS FLUID161
-
9 - AMNIOTIC FLUID AND CSF193
-
10 - SEMENALYSIS118
-
11 - FECALYSIS129
-
12 - MISC FLUIDS71
-
13 - UALITY ASSESSMENT AND MANAGEMENT IN URINALYSIS LABORATORY132
