URINALYSIS EXAM 1

When plotted on a Levy-Jennings chart, a control that has been left on the counter overnight instead of being refrigerated might show a/an:

Shift

Increased CV

Trend

Change in precision

Shift

true or false: Electrical current can pass through glass and wood.

false

Name three blood-borne pathogens.

HBV

HCV

HIV

All of the above

All of the above

Safety precautions observed in the urinalysis laboratory include all of the following except:

Wearing goggles or a face shield

Checking tube balance in the centrifuge

Centrifuging only uncapped tubes

Wearing a fluid-resistant lab coat

Centrifuging only uncapped tubes

Select all of the components in the chain of infection.

infectious agent

reservoir

portal of exit

means of transmission

portal of entry

susceptible host

all of them

Laboratory equipment and other inanimate objects serve as what in the chain of infection?

Host

Reservoir

Point of entry

Point of exit

Reservoir **also known as a fomite

true or false: When lifting heavy objects, laboratory workers should bend their knees.

true

The acceptable method for disposing of urine specimens is:

Autoclaving in the entire collection

Pouring down the sink followed by copious amounts of water

Placing the specimen in a biohazard bag

Diluting with sodium hypochlorite

Pouring down the sink followed by copious amounts of water

true or false: It is not necessary to change gloves when performing tasks on the same patient.

false

The ability to obtain the published result on a control sample is referred to as:

Precision

Accuracy

Standardization

Reliability

Accuracy

Which of the following is a practice that all laboratory workers must avoid?

Changing gloves that are soiled

Centrifuging conical tubes

Moving puncture-resistant containers

Manually recapping needles

Manually recapping needles

When a critical value is obtained in the laboratory:

The test should be repeated

The pathologist should be notified

A new specimen must be requested

The result must be reported to the health-care provider

The result must be reported to the health-care provider

Immediate information concerning the health hazards, flammability, and reactivity of a chemical can be obtained from the:

MSDS

NFPA symbol

CDC

OSHA

NFPA symbol

The least regulated level of Clinical Laboratory Improvement Amendments (CLIA) testing categories is:

Waived

Provider-performed microscopy

Moderate-complexity

High-complexity

Waived

A procedure with a coefficient of variation of 10% is considered:

Reliable

Precise

Confident

Imprecise

Imprecise

precise

A procedure is generally considered highly precise if its CV is tight and low, typically under 5%.

reliable

Reliability requires a combination of both high precision and high accuracy over time. A high CV compromises this.

confident

"Confident" is related to confidence intervals and statistical probability, but it is not the direct clinical term used to define a high percentage of relative dispersion in laboratory data.

The order of blood flow through the nephron is:

Afferent arteriole, peritubular capillaries, vasa recta, efferent arteriole

Efferent arteriole, peritubular capillaries, vasa recta, afferent arteriole

Peritubular capillaries, vasa recta, afferent arteriole, efferent arteriole

Afferent arteriole, efferent arteriole, peritubular capillaries, vasa recta

Afferent arteriole, efferent arteriole, peritubular capillaries, vasa recta

true or false: An increase in the plasma level of beta2 microglobulin correlates with decreased glomerular filtration.

true

The primary chemical affected by the renin-angiotensin-aldosterone system is:

Glucose

Potassium

Chloride

Sodium

Sodium

Tests to measure the tubular secretion of hydrogen ions include all of the following except:

pH

Titratable acidity

Urinary bicarbonate

Urinary ammonia

Urinary bicarbonate

What is the physical property measured by a vapor-pressure osmometer?

Vapor temperature

Dew point temperature

Osmotic pressure

Oncotic pressure

Dew point temperature

Given the following information, calculate the osmolar clearance: urine volume—720 mL in 24 hours, urine osmolality—700 mOsm, and plasma osmolality—300 mOsm.

1.0 mL/min

1.2 mL/min

1.8 mL/min

2.0 mL/min

1.2 mL/min

The p-aminohippuric acid (PAH) test is used to measure:

Glomerular filtration

Tubular reabsorption

Albumin excretion

Renal blood flow

Renal blood flow

Following a 2-hour infusion of p-aminohippuric acid (PAH), during which 200 mL of urine is collected, the urine PAH is 260 mg/dL, and the patient's plasma PAH is 0.8 mg/dL. Calculate the renal plasma volume.

525 mL/min

553 mL/min

614 mL/min

765 mL/min

553 mL/min

true or false: To calculate a creatinine clearance using the MDSD formula, the patient must collect at least a 2-hour urine specimen.

false

Production of antidiuretic hormone (ADH) is controlled by the:

Osmotic gradient of the medulla

Renin-angiotensin-aldosterone system

State of body hydration

Cells of the renal cortex

State of body hydration

Aldosterone regulates sodium reabsorption in the:

Proximal convoluted tubule

Descending loop of Henle

Ascending loop of Henle

Distal convoluted tubule

Distal convoluted tubule

Decreased production of aldosterone:

Produces a low urine volume

Produces a high urine volume

Increases ammonia excretion

Affects active transport of sodium

Produces a high urine volume

All of the following are endogenous clearance test substances except:

Urea

Creatinine

Inulin

Beta2 microglobulin

Inulin

John White donates one of his two healthy kidneys to his twin brother. His glomerular filtration rate can be expected to:

Decrease by 50%

Increase by 50%

Decrease gradually over 1 year

Remain within a normal range

Remain within a normal range

The results of a serum osmolality performed by both freezing-point and vapor-pressure osmometry do not agree. A possible cause of this discrepancy would be:

Increased ethanol

Increased lipids

Decreased lactic acid

Decreased potassium

Increased ethanol

list the components of the nephron in order of urine flow

bowman's capsule, proximal convoluted tubule, Loop of Henle, distal convoluted tubule, collecting tubule

What is not a function of the kidney?

waste removal

acid-base balance

hormone synthesis

digest food

H2O & electrolyte balance

nutrient retention

digest food

Name 3 substances that are filtered through the glomerulus.

glucose, bicarbonate, albumin, water, sodium

Name 2 substances that are NOT filtered through the glomerulus.

cellular components, large proteins

Name 4 substances that are reabsorbed in the tubules.

glucose, sodium, chloride, water, bicarbonate, albumin

true or false: two substances that are secreted in the tubules are: potassium (K) & hydrogen (H).

true

What role does the increased salt concentration in the medullary portion of the kidney play in the ability of the kidney to concentrate urine?

An increase in the salt concentration within the renal medulla allows for the body to create a strong hyperosmotic pressure. This allows the kidneys passively reabsorb water while simultaneously concentrating our urine. If our body was not able to increase salt concentration, then the kidneys would not be able to concentrate urine and this would result in an increase of water loss.

What change in the kidney's ability to concentrate urine would occur in the absence of antidiuretic hormone? Why?

Without ADH, the body would increase salt concentration and we would be in a state of dehydration. This means that ADH would not trigger the renal medulla to pull water out of the collecting duct and put it back into the bloodstream. Instead the water would be trapped inside the tubules of the kidney. Without ADH, the kidneys would also not be able to create concentrated urine (decreased) and we would have no change on any fluids coming through since they would be bypassing the osmotic concentration gradient. The end result would be a dehydrated patient with dilute urine and potential watery waste.

Explain the function and state the source of rennin.

Within the RAAS (renin-angiotensin-aldosterone system), renin functions to balance blood pressure, blood volume, and sodium. It is an enzyme that is made, stored, and secreted by specialized cells in the kidneys called the Juxtaglomerular cells. They are released when triggered by low blood pressure, low blood volume (sodium/chloride), and SNS activation in times of "fight or flight" response.

source and effect of aldosterone

adrenal cortex

Sodium reabsorption

source and effect of ADH (vasopressin)

hypothalamus

tubule permeability

true or false: The selective urine concentration process in the descending and ascending loops of Henle. The countercurrent mechanism allows for tubular concentration of the plasma filtrate by allowing for the secretion and reabsorption of H20 and NaCl in the tubules.

true

Which specific portion of the kidney is responsible for adjusting the final concentration of urine?

Nephron

Collecting duct

Glomerulus

Arterioles

Collecting duct

Given the following information, calculate the patient's free water clearance: urine volume—360 mL in 12 hours, urine osmolality—1,400 mOsm, and plasma osmolality—275 mOsm.

+0.5 mL/min

-1.5 mL/min

-1.0 mL/min

-2.0 mL/min

-2.0 mL/min

Concentration of the tubular filtrate by the countercurrent mechanism is dependent on all of the following except:

High salt concentration in the medulla

Water-impermeable walls of the ascending loop of Henle

Reabsorption of sodium and chloride from the ascending loop of Henle

Active transport reabsorption of sodium and glucose in the proximal convoluted tubule

Active transport reabsorption of sodium and glucose in the proximal convoluted tubule

A 12-hour urine specimen with a volume of 360 mL is collected for a creatinine clearance. What is the volume (V) used to calculate the clearance?

0.5 mL/min

1.0 mL/min

1.5 mL/min

2.0 mL/min

0.5 mL/min

For accurate evaluation of renal tubular concentrating ability, patient preparation should include:

Fasting

Fluid deprivation

Increased hydration

Abstaining from all medications

Fluid deprivation

Which of the following is not associated with the elimination of hydrogen ions?

Protein

Phosphate

Ammonia

Bicarbonate

Protein

Performing a clearance test using radionucleotides:

Requires the patient to abstain from all food

Does not require an infusion

Provides visualization of the filtration

Requires patient hospitalization

Provides visualization of the filtration

A PAH test result showing a renal plasma flow of 400 mL/min:

Is a normal result

May be falsely decreased from impaired tubular secretion

Should be corrected to correspond to the patient's body size

Indicates glomerular filtration of PAH

May be falsely decreased from impaired tubular secretion

The renal function that is most frequently the first affected by early renal disease is:

Renal blood flow

Glomerular filtration

Tubular reabsorption

Tubular secretion

Tubular reabsorption

Which of the following tests provides information similar to specific gravity?

Total colloid content

Protein concentration

Absorbance

Osmolality

Osmolality

Total acidity of a urine specimen is a combination of:

Titratable acidity and pH

Titratable acidity and ammonium ion

pH and total acidity

Total acidity and ammonium ion

Titratable acidity and ammonium ion

The glomerular filtrate is described as a:

Plasma filtrate containing glucose and protein

Protein-free ultrafiltrate of plasma

Selective filtrate of plasma containing urea

Plasma filtrate without glucose and protein

Protein-free ultrafiltrate of plasma

If a substance is completely filtered by the glomerulus and then completely reabsorbed by the tubules, the clearance of that substance will be:

Falsely decreased

Falsely increased

Normal

Zero

Zero

true or false: Hydrogen ions are filtered by the glomerulus and reabsorbed and secreted by the renal tubules.

true

To determine the amount of water that must be cleared to produce urine with the same osmolality as the ultrafiltrate, one should perform:

A free water clearance

A Mosenthal test

An osmolar clearance

A urine-to-plasma ratio

An osmolar clearance

The approximate number of nephrons contained in each kidney is:

100,000

500,000

1,000,000

5,000,000

1,000,000 (1 million)

Persons taking diuretics can be expected to produce:

Anuria

Polyuria

Nocturia

Oliguria

Polyuria

The three-glass collection is used for the diagnosis of:

Bladder cancer

Urinary tract infection

Diabetes mellitus

Prostate infection

Prostate infection

true or false: Polydipsia is a symptom of both diabetes mellitus and diabetes insipidus.

true

All of the following specimens are acceptable for a urine culture except:

Catheterized specimen

Timed specimen

Suprapubic aspiration

Midstream clean-catch specimen

Timed specimen

A urine specimen containing a large amount of precipitated amorphous material may have been preserved using:

Refrigeration

Phenol

Formalin

Toluene

Refrigeration

Which of the following urine chemicals will deteriorate when exposed to light?

pH

Leukocytes esterase

Bilirubin

Specific gravity

Bilirubin

All of the following are good preservatives of urinary cellular elements except:

Boric acid

Formalin

Sodium fluoride

Thymol

Sodium fluoride

Red blood cells will disintegrate more rapidly in urine that is:

Concentrated and acidic

Concentrated and alkaline

Dilute and acidic

Dilute and alkaline

Dilute and alkaline

true or false: A urine specimen label should include the date and time of collection.

true

The specimen of choice for routine urinalysis is the first morning urine because it:

Has a high volume

Is produced while the body is in a resting state

Is more dilute to prevent false-positive reactions

Is more concentrated to better detect abnormalities

Is more concentrated to better detect abnormalities

An unpreserved urine specimen left at room temperature overnight will have decreased:

Bacteria

Specific gravity and pH

Glucose and ketones

Color and specific gravity

Glucose and ketones

true or false: Urine contains organic and inorganic chemicals that can vary with body metabolic functions.

true

true or false: A specimen delivered to the laboratory in a gray-top Vacutainer is acceptable for urinalysis.

false

true or false: Medical laboratory scientists performing urinalysis can determine whether a specimen is urine from the presence of formed elements.

false

The first morning specimen from a patient with no history of symptoms for diabetes is positive for glucose. The patient should:

Be given a glucose tolerance test

Be asked to collect the second morning specimen

Be asked to collect a timed specimen

Be tested for renal tubular damage

Be asked to collect the second morning specimen

correct specimen type for routine urinalysis

random sample

correct specimen type for steroid determination

24 hour specimen

correct specimen type for diabetic screening

postprandial specimen

correct specimen type for proteinuria (specifically orthostatic)

first morning specimen

correct specimen type for estimation of number of formed elements

first morning specimen

correct specimen type for a culture for bacteria

clean catch sample

What is the time limit for urine to sit at room temperature prior to testing?

two hours

how does pH affect the urine constituent

an increase in bacteria: convert glucose to acid/old specimen

a decrease in bacteria making NH3

how does odor affect the urine constituent

increase Bacteria proliferation; makes ammonia

how does color affect the urine constituent

increases Oxidation or reduction metabolites (causes darkening)

how does clarity affect the urine constituent

Bacteria proliferation or solute precipitation (causes turbidity)

how does glucose affect the urine constituent

decreases cellular or bacteria glycolysis

how does ketones affect the urine constituent

decreases Bacteria metabolism of acetoacetate to acetone (volatile)

how does protein affect the urine constituent

none

how does bilirubin affect the urine constituent

decrease photo-oxidation

how does urobilirubin affect the urine constituent

decrease oxidation

how does WBC affect the urine constituent

decreased disintegration

how does nitrire affect the urine constituent

increases Bacterial production/converted to nitrogen

how does ammonia affect the urine constituent

increase bacterial production

how does bacteria affect the urine constituent

increase proliferation

how does RBC affect the urine constituent

decreases disintegration

true or false: If a urine specimen for routine urinalysis cannot be tested within the acceptable time limit at room temperature, it can be refrigerated for a week.

false

matching of each urine preservative with its primary clinical use: formalin

preserve sediment

matching of each urine preservative with its primary clinical use: boric acid

protein and uric acid