Clinical Chemistry (Electrolytes and Osmolality)

What is the normal renal threshold of sodium (measured in millimoles per liter)? A. 80-85 B. 90-110 C. 110-130 D. 135-148

Of the total serum osmolality, sodium, chloride, and bicarbonate ions normally contribute approximately what percent? A. 8 B. 45 C. 75 D. 92

The presence of only slightly visible hemolysis will significantly increase the serum level of which of the following electrolytes? A. Sodium B. Potassium C. Chloride D. Bicarbonate

Which of the following is not a component of the total anion content of serum? A. Acetoacetate B. Protein C. Lactate D. Iron

Which of the following is not associated with potassium? A. Has no renal threshold B. Increased serum level in acidosis C. Hemolysis causes false increase in serum levels D. Major anion of intracellular fluid

Which of the following is a spectrophotometric method for quantifying serum chloride? A. Ferric perchlorate B. Ammonium molybdate C. Bathophenanthroline D. Cresolphthalein complexone

Which of the following statements is false about the electrolyte chloride? A. Main anion of the extracellular fluid B. Can shift from the extracellular plasma to the intracellular fluid of red blood cells C. Unable to be reabsorbed by active transport D. Measured in serum, urine, and sweat

Using the following data: Na+ = 143 mmol/L; K+ = 4.9 mmol/L; Cl- = 105 mmol/L; and HCO-3 = 25 mmol/L, which of the following statements is false? A. Patient results are not acceptable. B. Anion gap is useful in detecting some disease states. C. Anion gap equals 18 mmol/L. D. Anion gap is useful for checking analytical error

A patient presents with Addison disease. Serum sodium and potassium analyses are performed. What would the results reveal? A. Normal sodium, low potassium levels B. Low sodium, low potassium levels C. Low sodium, high potassium levels D. High sodium, low potassium levels

Primary aldosteronism results from a tumor of the adrenal cortex. How would the extracellular fluid be affected? A. Normal sodium, decreased potassium levels B. Decreased sodium, decreased potassium levels C. Decreased sodium, increased potassium levels D. Increased sodium, decreased potassium levels

Which of the following conditions is not associated with hyponatremia? A. Addison disease B. Diarrhea C. Diuretic therapy D. Gushing syndrome

Of the total serum calcium, free ionized calcium normally represents approximately what percent? A. 10 B. 40 C. 50 D. 90

Measuring the tubular reabsorption of phosphate is useful in diagnosing diseases that affect which of the following organs? A. Liver B. Adrenal gland C. Thyroid gland D. Parathyroid gland

Which of the following does not have an effect on plasma calcium levels? A. Parathyroid hormone B. Vitamin D C. Calcitonin D. Aldosterone

Which of the following is an effect of increased parathyroid hormone secretion? A. Decreased blood calcium levels B. Increased renal reabsorption of phosphate C. Decreased bone resorption D. Increased intestinal absorption of calcium

The following laboratory results are obtained on a 60-year-old woman who is complaining of anorexia, constipation, abdominal pain, nausea, and vomiting: Ionized serum calcium—elevated Serum inorganic phosphate— decreased Urine calcium—elevated Urine phosphate—elevated What do these results suggest? A. Primary hyperparathyroidism B. Vitamin D deficiency C. Hypoparathyroidism D. Paget disease

Secondary hyperparathyroidism is often the result of A. Vitamin C deficiency B. Liver disease C. Renal disease D. Thyroid disease

Which of the following reagents is used to determine the concentration of serum inorganic phosphate? A. Ehrlich’s reagent B. Ammonium molybdate C. 8-Hydroxyquinoline D. Bathophenanthroline

Which of the following reagents is used in a colorimetric method to quantify the concentration of serum calcium? A. Cresolphthalein complexone B. Lanthanum C. Malachite green D. Amino-naphthol-sulfonic acid

Which of the following has an effect on plasma calcium levels? A. Sodium B. Inorganic phosphate C. Potassium D. Iron

A patient’s serum inorganic phosphate level is found to be elevated but the physician cannot determine a physiological basis for this abnormal result. What could possibly have caused an erroneous result to be reported? A. Patient not fasting when blood was drawn B. Specimen was hemolyzed C. Effect of diurnal variation D. Patient receiving intravenous glucose therapy

To what metal does ceruloplasmin firmly bind? A. Chromium B. Copper C. Zinc D. Iron

In iron-deficiency anemia, what would be the expected percent saturation of transferrin with iron? A. Less than 15 B. Between 30 and 40 C. Between 40 and 50 D. Greater than 55

What is the primary storage form of iron? A. Apotransferrin B. Myoglobin C. Ferritin D. Hemosiderin