Ciulla-AUBF Core Exam |Question and Answer| 100% Correct

Ciulla-AUBF Core Exam |Question and Answer| 100% Correct Why is the first-voided morning urine specimen the most desirable specimen for routine urinalysis? A. Most dilute specimen of the day and therefore any chemical compounds present will not exceed the detectability limits of the reagent strips B. Least likely to be contaminated with microorganisms because the bladder is a sterile environment C. Most likely to contain protein because the patient has been in the orthostatic position during the night D. Most concentrated specimen of the day and therefore it is more likely that abnormalities will be detected D. Most concentrated specimen of the day and therefore it is more likely that abnormalities will be detected First-voided morning urine - is most desirable for chemical and microscopic analysis since it is the most concentrated specimen. - Protein, nitrite and specific gravity, sediment examination prefers this sx. Glucose metabolism is better assessed in postprandial specimen. The physical characteristic of color is assessed when a routine urinalysis is performed. What substance is normally found in urine that is principally responsible for its yellow coloration? A. Bilirubin B. Melanin C. Carotene D. Urochrome D. Urochrome - yellow-brown pigment derived from urobilin - principally responsible for the yellow coloration of normal urine - excreted at a constant rate (no diurnal variation) - Color of normal urine (range from straw to deep amber) - Dependent on the concentrating ability of the kidney and the volume of urine excreted. In certain malignant disorders, what substance is found in the urine that turns the urine dark brown or black on exposure of the urine to air? A. Urobilinogen B. Indican C. Melanin D. Porphyrin C. Melanin - substance derived from tyrosine - responsible for the pigmentation of the eyes, skin, and hair Melanomas - malignancy - tumor or mole takes on a darkly pigmented appearance because of the melanin present. Metastatic melanoma - melanogen (colorless) precursor of melanin is excreted in the urine. - If the urine is allowed to stand at RT for 24 hrs, the melanogen is oxidized to melanin (dark brown or black) Qualitative screening tests = ferric chloride or sodium nitroprusside as the oxidation reagent systems. What is the expected pH range of a freshly voided urine specimen? A. 3.5-8.0 B. 3.5-9.0 C. 4.0-8.5 D. 4.5-8.0 D. 4.5-8.0 pH - representative symbol for the hydrogen ion conc. - kidney plays an important role in the maintenance of the acid-base balance of body fluids by either excreting or retaining hydrogen ions. A normally functioning kidney will excrete urine with a pH between 4.5 and 8.0, depending on the overall acid-base needs of the body Urine specimens should be analyzed as soon as possible after collection. If urine specimens are allowed to stand at room temperature for an excessive amount of time, the urine pH will become alkaline because of bacterial decomposition of A. Protein B. Urea C. Creatinine D. Ketones B. Urea Which term is defined as a urine volume in excess of 2000 mL excreted over a 24-hour period? A. Anuria B. Oliguria C. Polyuria D. Hypersthenuria C. Polyuria The reagent test strips used for the detection of protein in urine are most reactive to A. Albumin B. Hemoglobin C. Alpha-globulins D. Beta-globulins A. Albumin A urine specimen that exhibits yellow foam on being shaken should be suspected of having an increased concentration of A. Protein B. Hemoglobin C. Bilirubin D. Nitrite C. Bilirubin How should controls be run to ensure the precision and accuracy of the r