MLT GlobeUrinalysis & Body Fluids: Other body fluids (synovial, serous, semen, amniotic, fecal)
71 Urinalysis & Body Fluids MCQs on Other body fluids (synovial, serous, semen, amniotic, fecal) with answers and explanations.
The lecithin/sphingomyelin ratio in amniotic fluid is measured to assess:
Surfactant lecithin rises sharply late in gestation; a ratio of 2 or more suggests low risk of neonatal respiratory distress syndrome.
A synovial fluid is examined for monosodium urate crystals. Which microscope setup is needed to show their birefringence?
Birefringent crystals rotate plane-polarized light; a polarizer, analyzer and red compensator reveal this and distinguish urate (negative) from calcium pyrophosphate (positive) crystals.
The main sugar in seminal fluid that supplies energy for sperm motility is:
Fructose is secreted by the seminal vesicles; low levels suggest seminal vesicle obstruction or absence. Glucose is not the main seminal sugar.
Which test best assesses intestinal fat absorption?
Quantitative 72-hour fecal fat measures steatorrhea caused by malabsorption or pancreatic insufficiency. Amylase and lipase mainly reflect acute pancreatitis.
Normal synovial fluid forms a long string (4–6 cm) when dropped from a syringe. This high viscosity is due to:
Hyaluronic acid from synovial cells makes normal joint fluid viscous. Inflammation breaks down or dilutes hyaluronate, giving a short string.
Which condition most typically produces a pleural transudate?
Transudates result from changes in hydrostatic or oncotic pressure, as in heart failure, cirrhosis or nephrotic syndrome. Infection and cancer damage the membrane and give exudates.
Which instruction is correct for a man collecting a semen sample for fertility testing?
WHO advises 2–7 days of abstinence, collection into a clean non-toxic container, and delivery within about an hour at body-near temperature. Ordinary condoms contain spermicides that affect motility.
A pregnant woman reports fluid leakage. Which result best supports that the fluid is amniotic?
Amniotic fluid is alkaline (pH about 7.0–7.5), turning nitrazine blue, and forms a fern pattern when dried. Vaginal fluid is acidic, and urine has high urea and creatinine.
What is the usual upper limit of the WBC count in normal synovial fluid?
Normal synovial fluid has fewer than about 200 WBCs/µL, mostly mononuclear cells. Counts of 2,000–50,000/µL suggest inflammatory arthritis.
A chronic knee effusion from a patient with long-standing rheumatoid arthritis shows large, flat, rectangular plates with notched corners. These are:
Notched rectangular plates are typical of cholesterol, seen in chronic effusions. Calcium oxalate crystals are envelope- or dumbbell-shaped and occur in renal dialysis patients.
During arthrocentesis, the first tube is bloody but later tubes become clearer. This pattern most likely indicates:
Blood from needle injury is uneven and decreases as aspiration continues. True joint haemorrhage gives uniformly bloody fluid in all tubes.
A pleural exudate has a very low glucose (below 30 mg/dL or 1.7 mmol/L) in a patient with a long history of symmetrical joint disease. The most likely cause is:
Rheumatoid pleural effusions characteristically have very low glucose because of impaired glucose transport and high cell metabolism. Heart failure, cirrhosis and nephrotic syndrome cause transudates with normal glucose.
Amniotic fluid sent for bilirubin (ΔA450) measurement in suspected haemolytic disease of the fetus should be:
Bilirubin is broken down by light, which gives falsely low results. The specimen must be shielded from light immediately after collection.
Amniotic fluid alpha-fetoprotein is raised and acetylcholinesterase is positive. This most strongly suggests:
Leakage of fetal CSF through an open neural tube defect raises AFP, and acetylcholinesterase confirms neural tissue origin. Down syndrome is associated with low, not high, AFP.
A patient taking high-dose vitamin C has a guaiac fecal occult blood test. What effect is expected?
Vitamin C is a reducing agent that blocks oxidation of guaiac, so bleeding may be missed. Red meat and some vegetables with peroxidase activity cause false positives.
An infant has sweat chloride of 72 mmol/L on two separate tests. The best interpretation is:
Sweat chloride of 60 mmol/L or more supports cystic fibrosis; 30–59 mmol/L is intermediate and below 30 is unlikely. Repeat positive tests with clinical findings confirm the diagnosis.
Normal synovial fluid is best described as:
Normal joint fluid is clear, pale yellow and viscous because of hyaluronic acid. Cloudiness suggests inflammation or infection.
An abnormal accumulation of fluid in the peritoneal cavity is called:
Ascites is excess peritoneal fluid; it is collected by paracentesis. Pleural and pericardial effusions are fluid around the lungs and heart.
Thoracentesis is performed to collect which fluid?
Thoracentesis is needle aspiration of the pleural space. Paracentesis collects peritoneal fluid, pericardiocentesis pericardial fluid and arthrocentesis synovial fluid.
Most of the volume of semen is contributed by the:
The seminal vesicles provide about 60–70% of the ejaculate volume, including fructose. The prostate adds about 20–30%; sperm from the testes form only a small part.