Clinical Chemistry Flashcards
6 cards from real Laboratory Science practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Clinical Chemistry flashcards as text
Which electrolyte imbalance is most commonly associated with cardiac arrhythmias?
Answer: Hypokalemia or hyperkalemia
Both hypokalemia and hyperkalemia alter the cardiac action potential, leading to potentially life-threatening arrhythmias; potassium is the most critical electrolyte for cardiac rhythm.
What does an anion gap calculation help identify?
Answer: Cause of metabolic acidosis (distinguishing gap from non-gap acidosis)
Anion gap = Na⁺ − (Cl⁻ + HCO₃⁻); an elevated gap suggests accumulation of unmeasured anions (lactate, ketones, toxins), distinguishing high-gap from normal-gap metabolic acidosis.
Which pancreatic enzyme is elevated in acute pancreatitis and peaks within 24 hours of onset?
Answer: Amylase (rises faster but falls sooner)
Serum amylase rises within 2–12 hours of acute pancreatitis onset and peaks within 24 hours, though lipase is more specific and remains elevated longer.
What is the Henderson-Hasselbalch equation used for in clinical chemistry?
Answer: Relating blood pH to bicarbonate and dissolved CO₂ concentration
The Henderson-Hasselbalch equation (pH = pKa + log[HCO₃⁻/0.0307×pCO₂]) describes the relationship between pH, bicarbonate, and CO₂, critical for interpreting acid-base disorders.
Elevated serum bilirubin causing jaundice can be differentiated into pre-hepatic, hepatic, and post-hepatic types by measuring:
Answer: Direct (conjugated) vs. indirect (unconjugated) bilirubin fractions
Direct (conjugated) hyperbilirubinemia suggests hepatic or post-hepatic obstruction, while indirect (unconjugated) hyperbilirubinemia suggests pre-hepatic hemolysis or Gilbert syndrome.
Which lipoprotein fraction is considered 'good cholesterol' due to its cardioprotective role?
Answer: HDL (high-density lipoprotein)
HDL transports cholesterol from peripheral tissues back to the liver for excretion (reverse cholesterol transport), and higher HDL levels are associated with reduced cardiovascular risk.