Urinalysis and Body Fluids Flashcards
6 cards from real Medical Laboratory Technician Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Urinalysis and Body Fluids flashcards as text
A urinalysis is performed on a patient presenting with generalized edema and fatigue. The reagent strip shows 4+ protein, and the microscopic examination reveals numerous oval fat bodies and fatty casts. Which of the following conditions is most strongly indicated by these findings?
Answer: Nephrotic syndrome
Nephrotic syndrome is characterized by massive proteinuria (>3.5 g/day), hypoalbuminemia, edema, and hyperlipidemia. The profound glomerular damage allows large amounts of protein and lipids to pass into the urine, resulting in significant proteinuria, oval fat bodies (lipid-laden renal tubular epithelial cells), and fatty casts.
A urine reagent strip is positive for blood, but subsequent microscopic examination reveals no red blood cells. Which of the following is the most likely cause for this discrepancy?
Answer: Presence of myoglobin
The blood pad on the reagent strip detects the peroxidase-like activity of the heme portion of hemoglobin and myoglobin. In cases of rhabdomyolysis (muscle breakdown), myoglobin is released and filtered by the kidneys, causing a positive reagent strip result for blood. However, since there are no intact red blood cells, the microscopic exam will be negative.
A technologist receives four tubes of cerebrospinal fluid (CSF) collected via lumbar puncture. To minimize the chance of a false positive culture due to skin flora contamination from the procedure, which tube is typically designated for microbiology?
Answer: Tube 2
CSF is typically collected sequentially into 3 or 4 sterile tubes. Tube 1 is most likely to be contaminated with skin bacteria from the puncture site and is used for chemistry. Tube 2 is traditionally sent to microbiology, as the initial flow of fluid has likely cleared most contaminants. Tube 3 and 4 are generally used for hematology cell counts and other special studies.
A synovial fluid specimen is examined using a compensated polarizing microscope. The technologist observes needle-shaped crystals that are strongly negatively birefringent. When the crystals are aligned parallel to the slow axis of the compensator, they appear yellow. These findings are characteristic of which crystals?
Answer: Monosodium urate
Monosodium urate (MSU) crystals are characteristically needle-shaped and exhibit strong negative birefringence. Under compensated polarized light, they appear yellow when their long axis is parallel to the slow axis of the compensator and blue when perpendicular. The presence of these crystals is pathognomonic for gout.
A patient's urine specimen has a pH of 8.5 and a strong odor of ammonia. Microscopic analysis is most likely to reveal which of the following crystals?
Answer: Triple phosphate
Triple phosphate (magnesium ammonium phosphate, or struvite) crystals classically form in alkaline urine (pH > 7.0). Their shape is often described as a 'coffin-lid'. The formation is frequently associated with urinary tract infections caused by urease-producing bacteria (e.g., Proteus species), which break down urea into ammonia, raising the urine pH.
Which of the following sets of findings is most characteristic of a serous fluid classified as a transudate?
Answer: Clear appearance, fluid-to-serum protein ratio < 0.5
Transudates result from systemic conditions that alter hydrostatic or oncotic pressure (e.g., congestive heart failure, cirrhosis). They are typically clear and watery with a low protein content (fluid-to-serum protein ratio < 0.5), low LDH, and a low specific gravity (<1.015). Exudates are caused by local inflammatory processes and are cloudy with high protein, high LDH, and high cell counts.