Urinalysis Exam 1 Flashcards
Which is a disadvantage for using refrigeration as a preservative with urine specimens?
Precipitates amorphous phosphates and urates
Which of the following statements about the renin-angiotensin-aldosterone system is correct?
It increases blood pressure by increasing sodium and water retention
A urine specimen containing the substances indicated is kept unpreserved at room temperature for 4 hours. Identify the probable change to Nitrite.
Increases
Which of the following components is responsible for concentrating urine?
Juxtamedullary nephron
Where does active reabsorption of glucose, proteins, and sodium primarily occur?
Proximal convoluted tubule (PCT)
What are the two distinct areas of the kidney?
Cortex and medulla
A urine specimen containing the substances indicated is kept unpreserved at room temperature for 4 hours. Identify the probable change to Protein.
No change
Creatinine clearance can be used to measure:
Glomerular filtration rate
Which type of urine specimen is most concentrated?
First Morning
Which structure in the kidney is the site of plasma filtration?
Glomeruli
Anuria is most likely caused by?
Kidney damage or decreased cardiac output
What is GFR short for?
Glomerular filtration rate
Which of the following specimens usually eliminates contamination of the urine with entities from the external genitalia and the distal urethra?
Midstream “clean catch” specimen
A urine specimen containing the substances indicated is kept unpreserved at room temperature for 4 hours. Identify the probable change to Bacteria.
Increases
The required specimen for quantitative analysis of urinary constituents is the:
Timed specimen
To determine if a specimen is urine, measure the concentrations of:
Urea and creatinine
Where should labels on urine specimen containers be placed?
Container
What are the components of the GFR equation?
UV/P * (1.73/BSA) = GFR
(Uncorrected)
U = Urine creatinine level (mg/dL)
V = Urine volume (mg) / collection time (minutes)
P = Plasma/serum creatinine level (mg/dL)
(Corrected)
1.73 = average BSA
BSA = patient’s body surface area
Which organ is responsible for filtering blood in the urinary system?
Kidney
What is a common use for a first morning urine specimen?
Pregnancy screening
Which of the following is a term for decreased urine output of less than 400 mL/day?
Oliguria
The glomerular filtration barrier is composed of which of the following:
Capillary endothelium, basement membrane, and podocytes
Which specimen collection method is used to eliminate contamination and collect a midstream sample?
Midstream “Clean Catch”
Which hormone acts upon the collecting ducts to increase water reabsorption?
Antidiuretic hormone (ADH)
Blood flows through the nephron in the following order:
Afferent arteriole, efferent arteriole, peritubular capillaries, vase recta
Which pressure drives the plasma filtrate to leave the glomerular capillaries?
Hydrostatic pressure
What is the equation for GFR?
UV/P * (1.73/BSA) = GFR
What volume of urine is typically required for routine urinalysis?
10 – 15 mL
A urine specimen containing the substances indicated is kept unpreserved at room temperature for 4 hours. Identify the probable change to Glucose.
Decreases
Which analyte plays a role in all three acid-base regulation mechanisms in the kidneys?
Bicarbonate
Given the following information, calculated the creatinine clearance: 24-hour urine volume = 1000 mL/day. Serum creatinine = 2.0 mg/dL. Urine creatinine = 200 mg/dL.
69 mL/min
For general screening the most frequently collected specimen is a:
Random specimen
A urine specimen containing the substances indicated is kept unpreserved at room temperature for 4 hours. Identify the probable change to Urobilinogen.
Decreases
A 56-year-old male patient submits a 24-hour urine for creatinine clearance. The patient is a type 2 diabetic and is submitting a sample to accesses his kidney damage. The volume of the sample submitted is 2010 mL. The urine creatinine is 110 mg/dL, and the plasma creatinine is 1.8 mg/dL. The patient has a BSA of 1.85. What is the creatinine clearance?
80 mL/min
What happens to glucose in an unpreserved urine specimen left at room temperature overnight:
Glucose level decreases
Which of the following is not a function of the kidneys?
Production of insulin
Which of the following will not cause erroneous results in a 24-hour timed urine collection?
The collection starts and ends in the evening
What is the minimum volume of urine necessary per day to eliminate the body’s daily solutes?
500 mL
Which of the following can occur if a urine specimen is not properly preserved?
Bacteria proliferate and multiply
A urine specimen containing the substances indicated is kept unpreserved at room temperature for 4 hours. Identify the probable change to pH.
Increases
Which artery supplies blood to the kidneys?
Renal artery
What should be done if a urine specimen cannot be tested within 2 hours of collection?
Refrigerate until ready
Which type of urine collection involves puncturing the abdominal wall to collect directly from the bladder?
Suprapubic aspiration
The largest source of error when conducting a creatinine clearance test is:
Improperly timed urine specimens
The hormone aldosterone is responsible for:
Sodium retention
A urine specimen containing the substances indicated is kept unpreserved at room temperature for 4 hours. Identify the probable change to Ketones.
Decreases
The approximate number of nephrons contained in each kidney is:
1,000,000
Which specimen type is collected at a specific time and used to measure substances like urobilinogen when maximal excretion occurs?
Timed specimen
In the Renin-Angiotensin-Aldosterone (R-A-A) system, what triggers the release of renin?
Decreased blood volume
The functional unit of the kidney is the:
Nephron
The ureters connect the kidneys to which structure?
Bladder
What is the normal urine output per day in the healthy individual?
600 – 1800 mL/day
What does a high serum level of Cystatin C indicate?
Decreased glomerular filtration rate (GFR)
Failure to empty the bladder before beginning the collection of a timed urine specimen will:
Cause falsely increased results
What percent of the original ultrafiltrate formed in the urinary space actually is excreted as urine?
1%
The recommended specimen for routine urinalysis testing is the:
First morning specimen
A urine specimen containing the substances indicated is kept unpreserved at room temperature for 4 hours. Identify the probable change to Bilirubin.
Decreases
What is the role of podocytes in the kidney?
Part of the glomerular filtration barrier
Before analysis, a refrigerated urine specimen must be:
Returned to room temperature
An individual is considered to be in complete kidney failure if they have an eGFR of:
<15 mL/min/1.73m2
What percentage of urine is made up of water?
95%
The primary chemical affected by the renin-angiotensin-aldosterone system is:
Sodium
