ClinLab Block 2 Flashcards
Kidney’s selectively clear what waste?
Kidney’s maintain homeostatic regulation by ?
Urea
Water/electrolyte balance
Acid/base balance
What are the four functions of the nephron?
Concentrate urine
Filter blood
Excrete waste products
Reabsorb nutrients
What are four factors that affect renal function?
Renal blood flow
Glomerular filtration
Tubular reabsorption
Tubular secretion
Substances with a molecular weight less than ______ pass into filtrate
70K daltons
Glomerular filtration rate is maintained through what three methods?
Renal autoregulation using myogenic control
Extrinsic neural responses to stress
RAAS mechanism to increase SBP by inc Na reabsorption
Tubular reabsorption begins when _______ and involves near total reabsorption of ___ and is hormonally regulated____ and ___
Filtrate enters PCT
Organic nutrients
Water and Ions
When the plasma level of a substance exceeds the renal threshold, what happens?
What happens if the plasma level of a substance stays above the renal threshold?
Substance appears in urine
Active transport can’t reabsorb substance from filtrate
Define Tubular Secretion
What are the two functions of Tubular Secretion?
Active transport of substances from peri-tubular capillaries into tubular filtrate
Eliminate substances no found in blood
Regulate acid-base balance by secreting H+ and NH4+
Where does final concentration of urine begin?
How is this process regulated?
Average adult daily volume of urine output per day?
Late DCT, continues through collecting duct
ADH
1200-1500mL w/ pH slightly acidic
If we were so over hydrated we would have no ADH which would cause a decrease in what factors?
Osmality ADH release Number of aquaporins Water reabsorption in CD Large volume of diluted urine (Exact opposite if max ADH is present)
Define Polyuria
Define Oliguria
Define Anuria
Inc urine output >2.5L/day
Dec urine output <400ml/day
Severe low output <100ml/day
Diabetes insipidus results from decreased production of ? causing urine to take on a ? appearance
ADH
Truly diluted and low SpecGrav
Whats the difference in DM and DI urine samples?
DM= Looks dilute, high osmality DI= Truly diluted and low SpecGrav
When is oliguria usually seen?
Anuria can be a result of what two factors?
Dehydration
Serious kidney damage
Decreased blood flow to kidneys
Purpose of Random Samples
Purpose of First Morning samples
Routing Screening
Routine screening, Pregnancy, Orthostatic protein
Fasting specimens are collected for?
Why are 2H postprandial collected?
Diabetic screening/monitoring
Diabetic monitoring
When are glucose tolerance tests performed?
Why are 24hr urine collections performed?
Accompanied with blood samples in glucose tolerance tests
Quantitative chemical tests
Why are catheter urine samples performed?
When are mid-stream collections taken?
Bacterial culture
Routine, Bacterial culture
Why are suprapubic aspiration urine samples taken?
Why are three-glass collections taken?
Urine specimens need to be delivered to the lab within _hrs or need to be ___
Bladder urine for bacterial infections, Cytology
Prostate infections
2hrs or refrigerated at 2-6*C
What are some reasons specimens will be unaccepted by the lab?
Not labeled Labels don't match Contaminated Insufficient quantity Improper transportation
What factors will INCREASE in a urine sample?
Odor- bacteria breaking urea down to ammonia
pH- urea breakdown produces loss of CO2
Nitrite- multiplication of nitrate reducing bacteria
Bacteria- multiply
Urine samples under go what three tests?
Physical exam, Chemical analysis, Microscopic
What give urine it’s normal yellow color?
Normal urine color ranges are ?
Variations are due to ?
Urochrome- product of endogenous metabolism which is naturally produced at a constant rate
Pale yellow to straw/very dark yellow to amber
Hydration levels
What causes urine samples to be dark amber or orange?
Conjugated bilirubin
Photo-oxidation of urobilinogen to urobilin produces color change too