CLS304 - Module 3 (Powerpoints - Part 2)

what is the ultrafiltrate of plasma?

urine

approximately how many mL of filtered plasma do kidneys convert?

170,000mL

what is the average daily urine output?

1200mL

in normal urine, about what percent is water?

95%

in normal urine, about what percent are solutes?

5%

what is the major organic solute in urine?

urea (protein, amino acid breakdown)

what makes up approximately one half of the dissolved solids in urine?

urea

list 3 ions found in urine.

inorganic chloride, sodium, potassium

what two substances identify a fluid as urine?

urea and creatinine

what may contain cells, crystals, mucus, and bacteria?

urine

an increase in cells, crystals, mucus, or bacteria in urine may be indicative of ____.

disease

what is determined by the body’s state of hydration?

urine volume

what is the normal urine volume?

600-800mL/day

what is the relationship between the excretion of solutes and water in urine volume?

amount of solutes excreted increases as water required to excrete them increases

what refers to the inability of kidneys to change specific gravity of plasma ultrafiltrate

isothenuria

what is the specific gravity of plasma ultrafiltrate?

1.010

what causes the normal yellow color of urine?

urochrome

dark yellow refers to ____ urine while pale yellow refers to ____ urine.

concentrated; dilute

what is a lipid-soluble pigment in plasma excreted in urine?

urochrome

what aspect of urine is not normally included on a report?

foam

what is produced when normal urine is shaken?

white foam that rapidly dissipates

white foam refers to ____ in urine while yellow foam refers to ____ in urine.

albumin; bilirubin

what describes the cloudiness of urine caused by suspended particulate matter that scatters light?

clarity

what is the clarity of normal urine specimens?

clear

contamination from skin or vaginal secretions, bacterial growth, or fecal material may cause urine’s clarity to be ____.

cloudy

precipitation of dissolved solutes, x-ray contrast media may cause urine’s clarity to be ____.

cloudy

RBCs, WBCs, epithelial clots, bacteria, and casts may cause urine’s clarity to be ____.

cloudy

what type of odor does normal urine have

aromatic

why does urine on standing becomes odorous?

bacterial conversion of urea to ammonia

what may change the odor of urine?

ingestion of certain foods or drugs

what odor do ketones produce for urine?

sweet or fruity

what odor do amino acid disorders produce for urine?

odd odors

what refers to amount of solutes present in volume of water excreted?

concentration

what is a crude indicator of concentration in urine?

color

what is an expression of concentration in terms of density?

specific gravity

what refers to mass of solutes present per volume of solution?

specific gravity

what is the ratio of urine density to density of an equal volume of pure water under specific conditions?

specific gravity

what is affected by solute particles and molecular size?

specific gravity

what is the equation of specific gravity?

SG = density of urine / density of equal volume of pure water

what refers to the concentration of a solution expressed in terms of osmoles of solute particles per kilogram (kg) of water?

osmolality

what is often used for convenience due to low osmolality of biological solutions?

milliosmoles (mOsm)

what is the normal urine osmolality value?

275 to 900 mOsm/kg

what is the normal serum osmolality value?

275 to 300 mOsm/kg

____ osmolality remains relatively constant while ____ osmolality depends on diet, fluid intake, and physical activity.

serum; urine

list 4 principal uses of osmolality.

evaluate renal concentrating ability of kidneys, monitor renal disease, monitor fluid and electrolyte balance, differentially diagnose cause of polyuria

what is determined by measuring a colligative property of solution such as freezing point depression or vapor pressure depression?

osmolality

what is the most common method for chemical testing?

chemical analysis reagent strips

qualitative results of chemical analysis reagent strips is based on color change. true or false?

true

some interfering substances such as ascorbic acid need to be detected or eliminated for chemical analysis reagent strips. true or false?

true

plastic strip with reagent-impregnated pads dipped in urine will result in visual color change. true or false?

true

what can confirm results obtained by reagent strip testing?

tablet/liquid tests

what is an alternative method for highly pigmented urine?

tablet/liquid tests

what tests can be used when strip testing is not sensitive enough? provide an example.

tablet/liquid tests; ictotest tablets for bilirubin

tablet/liquid tests can be used when test specificity differs from strip method (sulfosalicylic acid test). true or false?

true

what tablet/liquid test confirms ketones?

acetest

what only measures ionic solutes (e.g., sodium, potassium, chloride, ammonium)?

specific gravity

when a chemical analysis reagent strip is immersed in urine, electrons are released from reagent in proportion to ionic concentration changing the pad color. true or false?

false (protons are released)

what is the range of normal pH for urine?

4.5-8.0; usually slightly acidic but more alkaline after meals

what can affect the stability of formed elements?

pH

what test should be performed on fresh urine?

pH

pH is based on a double indicator system. true or false?

true

pH uses bromothymol blue and methyl red. true or false?

true

what color changes does pH produce? (include pH values)

orange (pH 5.0) to green (pH 7.0) to blue (pH 9.0)

what refers to RBCs in urine?

hematuria

what refers to free hemoglobin in urine?

hemoglobinuria

based on heme’s pseudoperoxidase activity, the pad has what 2 components?

chromogen and peroxide

based on heme’s pseudoperoxidase activity, pseudoperoxidase reduces ____ while ____ is oxidized—resulting in a color change.

peroxide; chromogen

what is known to interfere with the reaction based on heme’s pseudoperoxidase activity?

ascorbic acid

normally there is lots of WBCs in urine. true or false?

false (only a few)

what is susceptible to lysis? although they are not seen, what will be released?

WBCs; leukocyte esterase

>20/μl is an indication of pathologic process. true or false?

true

what is able to detect as few as 10 WBCs/μl?

leukocyte esterase

what is the principle based on action of leukocyte esterase?

cleave an ester in the pad and result in color change

what component in urine can form nitrite?

nitrate-reducing bacteria

what are the two requirements of a nitrite test?

bacteria present must be nitrate-reducers and adequate time in bladder to be reduced

what is often the first sign of kidney disease?

urine protein

what test is most sensitive to albumin?

strip test

both diabetes and high blood pressure can cause damage to the kidneys, which leads to ____.

proteinuria

what refers to low levels of albumin?

microalbumin

in regards to microalbumin, routine test strips are unable detect albumin in urine that is ____.

<1 to 2 mg/dL

what test detects low-level albuminuria?

sensitive albumin tests

tests for microalbumin is often used for patients with ____. why?

diabetes; to screen for signs of early kidney damage

glucose is not seen in normal urine. true or false?

true

what will appear if the plasma level in urine is over the threshold of 160 to 180 mg/dL?

glucose

in regards to glucose tests, the principle based on a double sequential enzyme reaction that is specific for glucose. true or false?

true

glucose oxidase in pad oxidizes glucose to form hydrogen peroxide and gluconic acid resulting in a color change. true or false?

true

what tests detects sugars (except sucrose), ascorbic acid, cysteine, and some drugs (e.g., galactosemia)?

tests for reducing substances

what are the breakdown products from large amounts of fatty acids?

ketones

list 3 types of ketones.

acetoacetate, acetone, beta-hydroxybutyrate

which ketone is not detected by strip tests?

beta-hydroxybutyrate

in regards to ketones, what are the two principles based on nitroprusside reaction?

causes color change from beige to purple and acetest

what is water soluble and found in urine?

direct (conjugated) bilirubin

what conjugates bilirubin?

liver

what is not water soluble? why?

indirect bilirubin; bound to albumin in plasma so it is too large to filter at kidneys

what causes urine to be dark yellow to brown?

bilirubin

what is a product of bilirubin that forms in the intestine?

urobilinogen

what can indicate hemolytic anemia in addition to cirrhosis an hepatitis?

presence of urobilinogen in urine tests

what are the room conditions for the appropriate manual reagent strip testing technique?

good lighting, preferably fluorescent; avoid direct sunlight

in what conditions should the urine specimen be for the appropriate manual reagent strip testing technique?

room temperature

what is the first step for the appropriate manual reagent strip testing technique?

using uncentrifuged urine, mix specimen well