kidney function test Flashcards
functional unit of the kidney
Nephron
responsible for REABSORPTION of Na+, Cl-, HCO3, and other anions, glucose, amino acids and proteins, urea and uric acid
PROXIMAL CONVULATED TUBULE
how many liters of dilute uine delivered to ascending loop of henle
25 liters
FINAL SITE for either concentrating or diluting urina
collecting duct
FUNCTION of the kidneys
- Ellimination of waste products
- Maintenance of blood volume
- Maintenance of acid base balance
- Maintenance of electrolyte balance
- Endocrine function
Tests for GLOMERULAR FILTRATION RATE
- CLEARANCE
- CYSTATIN C
- BETA TRACE PROTEIN
BEST OVERALL INDICATOR OF KIDNEY FUNCTION
GFR
measure of the clearance of the normal molecule that is not bound to protein but freely filtered by the glomerulus neither reabsorbed nor secreted by the tubu;les
Glomerular Filtration Rate
how many liters thus glomerular filtrate produced daily
150 liters
how many water thus glomerulus filtered daily
180 liters
alternatives to inulin clearance
- radioactive markers 125I- iothalamate and 99 mtc-DTPA
- iohexol and chromium51-labeled Edta (51Cr-EDTA)
- nonradiolabeled iothalamate
how many creatinine excreted per day?
1.2 - 1.5 g creatinine excreted/day
creatinine REFERENCE METHOD
INULIN CLEARANCE
NOT ROUTINELY DONE because of the necessity for continuous IV infusion and Timed urine collection over many hours
inulin clearance
excellent measure of renal function
creatine clearance
ESTIMATE the amount of plasma that must be flowed through the kidney glomeruli/minutes
creatinine clearance
measure completeness of 24 hour urine collection
CREATININE CLEARANCE
PROGRESS OF RENAL DISEASE OR RESPONSE TO THERAPY
UREA CLEARANCE
increase MORE rapidly than creatinine in the early stages of GFR impairement
cystatin c
to asses GFR among PEDIATRICS and ELDERLY patients and renal transplant patients
CYSTATIN C
low molecular weight glycoprotein
beta trace protein
low molecular weight protease inhibitor
cystatin c
function as PROSTAGLANDIN D SYNTHASE
BETA TRACE PROTEIN
increased:
a. Acute and chronic renal failure
b. diabetic nephropathy
cystatin c
increased: a. burn b. pregnancy c, carbon monoxide poisoning d. high cardiac output
creatine clearance
increased:
renal disease
beta trace protein
test for RENAL BLOOD FLOW
- BUN
- CREATININE
- BUA
FIRST METABOLITE TO ELEVATE IN kidney disease?
blood urea nitrogen (BUN)
how many UREA excreted DAILY?
25g
BUN:Crea ratio
10:1 OR 20:1
It is added to ENHANCE THE COLOR DEVELOPMENT IN BUN???????
THIOSEMICARBAZIDE
FERRIC IONS
creatinine is derived from?
creatine (alpha methyl guanidoacetic acid)
NOT easily removed by the dialysis
creatinine
easily removed by the dialysis
bun
soley WASTE PRODUCT/ not reused in body metabolism
creatinine
what are the JAFFE REAGENT?
- saturated picric acid
2. 10% NaOH
SODIUM aluminum silicate?
a. Lloyd’s reagent
b. Fuller’s earth reagent
SODIUM aluminum silicate?
a. Lloyd’s reagent
sensitive but NOT SPECIFIC in methods of creatinine?
a. folin wu method
b. llyod’s or fuller method
c. kinetic jaffe method
sensitive but NOT SPECIFIC in methods of creatinine?
a. folin wu method
methods form JANOVSKY like reaction?
a. kinetic jaffe medthod
b. direct jaffe method
c. glutamate dehydrogenase method
methods form JANOVSKY like reaction?
a. kinetic jaffe medthod
potential to replace jaffe method? specific than jaffe method? a. idms b. creatinine aminohyrolase method/ CK method c. creatinase hydrogen peroxide method
potential to replace jaffe method?
specific than jaffe method?
c. creatinase hydrogen peroxide method
elevated concentrations of nitrogenous substances?
azotemia
causes:
> acute/ chronic renal DISEASE
>glomerulonephritis
renal azotemia
causes:
>dehydration
> congestive heart failure
> shock
pre renal azotemia
responsible for the changes in RED CELL SHAPE WITH BURR CELLS(ECHNOCYTES) AND ELLIPSOIDAL CELLS
UREMIA
MARKED ELEVATION OF PLASMA UREA AND NITROGENOUS WASTE PRODUCT, ACIDEMIA AND ELECTROLYTE IMBALANCE
UREMIA
good indicator of nitrogen intake and state of hydration
a. creatinine
b. bua
c. bun
good indicator of nitrogen intake and state of hydration
c. bun
used to evaluate fetal kidney maturity?
a. creatinine
b. bun
c. bua
used to evaluate fetal kidney maturity?
a. creatinine
(+) BIREFRINGENT CRYSTALS IN SYNOVIAL FLUID?
a. gout
b. increased renal metabolism
c. lesch nylan syndrome
(+) BIREFRINGENT CRYSTALS IN SYNOVIAL FLUID?
a. gout
how many URIC ACID excreted normally?
1 gram
major product or PURINE catabolism?
a. bun
b. creatinine
c. bua
major product or PURINE catabolism?
c. bua
hypouricemia, except?
a. fanconi’s syndrome
b. lesch nylan syndrome
c. hodgkin syndrome
d. wilson’s disease
hypouricemia, except?
b. lesch nylan syndrome
specific method in bua?
uricase method
specimen for concentration test?
first morning urine
osmolality is determined by measuring the colligative property such as__________
freezing point
vapor pressure
osmotic pressure
boiling point
is the difference between MEASURED and CALCULATED plasma osmolality?
osmolal gap
POPULAR METHOD in osmolality
a. vapor pressure osmometry
b. freezing point osmometry
c. boiling point osmometry
POPULAR METHOD in osmolality
b. freezing point osmometry
measures the RENAL PLASMA FLOW
para amino hippurate test (diodrast test)
measures excretion of the dye proportional to renal tubular mass
phenolsulfonthalein dye test
In this method it requires clearance of the dye
a. phenolsulfonthalein dye test
b. para amino hippurate test (diodrast test)
In this method it requires clearance of the dye
b. para amino hippurate test (diodrast test)
is the SIMPLEST TEST OF RENAL CONCENTRATING ABILITY?
a. phenolsulfonthalein dye test
b. para amino hippurate test (diodrast test)
c. specific gravity
d. osmolality
is the SIMPLEST TEST OF RENAL CONCENTRATING ABILITY?
c. specific gravity
