Question 1

Which of the following blood drawing tubes is most appropriate for measuring magnesium?

Accepted Answer

A)  Royal blue tube with K2-EDTA 
B)  Lavender top tube with K2-EDTA 
C)  Plain red top with no additives 
D)  Gray top tube with sodium fluoride/potassium oxalate 
A)  Royal blue tube with K2-EDTA 
B)  Lavender top tube with K2-EDTA 
C)  Plain red top with no additives 
D)  Gray top tube with sodium fluoride/potassium oxalate C

Question 2

Which of the following is an effect of increased parathyroid secretion?

Accepted Answer

A)  Decreased intestinal absorption of calcium 
B)  Increased intestinal absorption of calcium 
C)  Decreased blood calcium levels 
D)  Decreased bone resorption 
A)  Decreased intestinal absorption of calcium 
B)  Increased intestinal absorption of calcium 
C)  Decreased blood calcium levels 
D)  Decreased bone resorption B

Question 3

Which of the following additives is preferred when drawing blood samples to measure parathyroid hormone (PTH)?

Accepted Answer

A)  Acid citrate dextrose because PTH is least stable using this additive 
B)  Potassium (3)-EDTA (K3-EDT
A)  because PTH is most stable using this additive 
C)  Sodium citrate because PTH is most stable using this additive 
D)  Sodium fluoride/potassium oxalate because PTH will complex with oxalate to increase its stability 
A)  Acid citrate dextrose because PTH is least stable using this additive 
B)  Potassium (3)-EDTA (K3-EDT
A)  because PTH is most stable using this additive 
C)  Sodium citrate because PTH is most stable using this additive 
D)  Sodium fluoride/potassium oxalate because PTH will complex with oxalate to increase its stability B

Question 4

Which of the following is considered a significant problem with using biomarkers of bone turnover in the management of patients with osteoporosis in a clinical setting?

Accepted Answer

A)  They can be repeated over short time intervals thus providing quick results. 
B)  They are noninvasive. 
C)  They require no special patient preparation. 
D)  The measurements are affected by several preanalytical variables both controllable and uncontrollable. 
A)  They can be repeated over short time intervals thus providing quick results. 
B)  They are noninvasive. 
C)  They require no special patient preparation. 
D)  The measurements are affected by several preanalytical variables both controllable and uncontrollable.

Question 5

Which of the following feedback mechanisms regulate the production of 1, 25(OH) 2D3?

Accepted Answer

A)  Negative feedback mechanism associated with circulating levels of calcium and inorganic phosphorus 
B)  Negative feedback mechanism associated with circulating levels of calcitonin 
C)  Negative feedback mechanism associated with circulating levels of magnesium 
D)  Positive feedback mechanism associated with circulating levels of calcium and inorganic phosphorus 
A)  Negative feedback mechanism associated with circulating levels of calcium and inorganic phosphorus 
B)  Negative feedback mechanism associated with circulating levels of calcitonin 
C)  Negative feedback mechanism associated with circulating levels of magnesium 
D)  Positive feedback mechanism associated with circulating levels of calcium and inorganic phosphorus

Question 6

"A progressive systemic skeletal disease characterized by low bone mass and micro architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptible to fracture" describes which of the following disorders?

Accepted Answer

A)  Osteosarcoma 
B)  Osteoporosis 
C)  Renal osteodystrophy 
D)  Paget's disease 
A)  Osteosarcoma 
B)  Osteoporosis 
C)  Renal osteodystrophy 
D)  Paget's disease

Question 7

A blood specimen is received in the laboratory from a maternity patient in the obstetric unit with blood magnesium ordered by the attending physician. The serum magnesium level is 5.0 mg/dL (RI = 1.6 - 2.6 mg/dL). Which of the following explains the elevated serum magnesium?

Accepted Answer

A)  The patient has primary hyperparathyroidism. 
B)  The patient has had a massive heart attack. 
C)  The patient is on magnesium sulfate intravenous infusion because she is experiencing pre-eclampsia. 
D)  The patient has Paget's disease. 
A)  The patient has primary hyperparathyroidism. 
B)  The patient has had a massive heart attack. 
C)  The patient is on magnesium sulfate intravenous infusion because she is experiencing pre-eclampsia. 
D)  The patient has Paget's disease.

Question 8

Biomarkers of bone formation include which of the following?

Accepted Answer

A)  Hydroxproline 
B)  Carboxyl-terminal cross-linked telopeptide of type I collagen 
C)  Bone sialoprotein 
D)  Osteocalcin 
A)  Hydroxproline 
B)  Carboxyl-terminal cross-linked telopeptide of type I collagen 
C)  Bone sialoprotein 
D)  Osteocalcin

Question 9

Which of the following laboratory results reflects a patient diagnosed with rickets as a result of a dietary deficiency of vitamin D?

Accepted Answer

A)  Increased serum total calcium, decreased serum total alkaline phosphatase, and increased serum inorganic phosphorus 
B)  Decreased serum PINP, decreased serum TRAP, and decreased serum DPD 
C)  Normal serum PINP, normal serum TRAP, and normal serum DPD 
D)  Increased serum PINP, increased serum TRAP, and increased serum DPD 
A)  Increased serum total calcium, decreased serum total alkaline phosphatase, and increased serum inorganic phosphorus 
B)  Decreased serum PINP, decreased serum TRAP, and decreased serum DPD 
C)  Normal serum PINP, normal serum TRAP, and normal serum DPD 
D)  Increased serum PINP, increased serum TRAP, and increased serum DPD

Question 10

Pyridinoline, carboxy, amino-terminal cross-linked telopeptide of type I collagen, and tartrate-resistant acid phosphatase are all examples of which of the following?

Accepted Answer

A)  Biomarkers of osteoblast conversion to osteoclast 
B)  Biomarkers of formation 
C)  Biomarkers of resorption 
D)  Cancer antigens associated with bone tumors 
A)  Biomarkers of osteoblast conversion to osteoclast 
B)  Biomarkers of formation 
C)  Biomarkers of resorption 
D)  Cancer antigens associated with bone tumors

Question 11

Which of the following is an example of a controllable preanalytical variable associated with specimen collection for bone biomarker testing?

Accepted Answer

A)  Diet 
B)  Age 
C)  Gender 
D)  Fractures 
A)  Diet 
B)  Age 
C)  Gender 
D)  Fractures

Question 12

Which of the following compounds promote osteoclast formation?

Accepted Answer

A)  Bisphosphonate 
B)  1, 25-dihydroxy Vitamin D3 
C)  Calcitonin 
D)  Osteoprotegerin {OPG} 
A)  Bisphosphonate 
B)  1, 25-dihydroxy Vitamin D3 
C)  Calcitonin 
D)  Osteoprotegerin {OPG}

Question 13

Heat inactivation and chemical inhibition are two methods used to measure which of the following analytes?

Accepted Answer

A)  Acid phosphatase isoenzymes 
B)  Alkaline phosphatase isoenzymes 
C)  Creatine kinase isoenzymes 
D)  Osteocalcin 
A)  Acid phosphatase isoenzymes 
B)  Alkaline phosphatase isoenzymes 
C)  Creatine kinase isoenzymes 
D)  Osteocalcin

Question 14

Blood levels of ionized calcium are sensitive to which of the following?

Accepted Answer

A)  Barometric pressure 
B)  Partial pressure of carbon dioxide 
C)  Magnesium concentration 
D)  pH and temperature 
A)  Barometric pressure 
B)  Partial pressure of carbon dioxide 
C)  Magnesium concentration 
D)  pH and temperature

Question 15

Which of the following do calcium, phosphorus, and magnesium have in common?

Accepted Answer

A)  They all exist in circulation as only free or ionized forms. 
B)  They all exist as free or ionized forms, bound to proteins and complexes to radicals, e.g., sulfates to form salts. 
C)  Calcium exists as bound and free only, phosphorus exists only as bound and complexes to radical to form salts and magnesium exists as free or ionized forms, bound to proteins and complexes to radicals to form salts. 
D)  Calcium blood levels are regulated by parathyroid hormones, phosphorus is regulated by testosterone, and magnesium is regulated by insulin. 
A)  They all exist in circulation as only free or ionized forms. 
B)  They all exist as free or ionized forms, bound to proteins and complexes to radicals, e.g., sulfates to form salts. 
C)  Calcium exists as bound and free only, phosphorus exists only as bound and complexes to radical to form salts and magnesium exists as free or ionized forms, bound to proteins and complexes to radicals to form salts. 
D)  Calcium blood levels are regulated by parathyroid hormones, phosphorus is regulated by testosterone, and magnesium is regulated by insulin.

Question 16

Monitoring intraoperative PTH is useful for:

Accepted Answer

A)  Surgical management of primary hyperparathyroidism. 
B)  Surgical management of thyroid disease. 
C)  Surgical management of prostate cancer. 
D)  Surgical management of coronary heart disease. 
A)  Surgical management of primary hyperparathyroidism. 
B)  Surgical management of thyroid disease. 
C)  Surgical management of prostate cancer. 
D)  Surgical management of coronary heart disease.

Question 17

Which of the following statements best illustrates the diagnostic criteria for primary hyperparathyroidism?

Accepted Answer

A)  No serum PTH detected and no serum calcium detected 
B)  Detectable amounts of serum PTH concomitant with elevated total serum calcium 
C)  Elevated total serum calcium only 
D)  A normal level of serum PTH and serum calcium 
A)  No serum PTH detected and no serum calcium detected 
B)  Detectable amounts of serum PTH concomitant with elevated total serum calcium 
C)  Elevated total serum calcium only 
D)  A normal level of serum PTH and serum calcium

Question 18

Which of the following instruments can measure calcium, magnesium, and phosphorus in blood samples?

Accepted Answer

A)  Fluorimeter 
B)  Osmometer 
C)  Atomic absorption spectrometer 
D)  Refractometer 
A)  Fluorimeter 
B)  Osmometer 
C)  Atomic absorption spectrometer 
D)  Refractometer

Question 19

Which of the following laboratory results best represents a patient with Paget's disease?

Accepted Answer

A)  Decreased urinary hydroxyproline and increased serum alkaline phosphatase 
B)  Increased urinary hydroxyproline and decreased serum alkaline phosphatase 
C)  Normal urinary hydroxyproline and normal serum alkaline phosphatase 
D)  Decreased urinary hydroxyproline and decreased serum alkaline phosphatase 
A)  Decreased urinary hydroxyproline and increased serum alkaline phosphatase 
B)  Increased urinary hydroxyproline and decreased serum alkaline phosphatase 
C)  Normal urinary hydroxyproline and normal serum alkaline phosphatase 
D)  Decreased urinary hydroxyproline and decreased serum alkaline phosphatase

Question 20

Which of the following reagents is used to determine the concentration of serum magnesium?

Accepted Answer

A)  Biuret 
B)  Bathophenanthroline 
C)  Methylthymol blue 
D)  Phosphomolybdate 
A)  Biuret 
B)  Bathophenanthroline 
C)  Methylthymol blue 
D)  Phosphomolybdate

Exam 14: Mineral and Bone Metabolism

Which of the following blood drawing tubes is most appropriate for measuring magnesium?

Which of the following is an effect of increased parathyroid secretion?

Which of the following additives is preferred when drawing blood samples to measure parathyroid hormone (PTH)?

Which of the following is considered a significant problem with using biomarkers of bone turnover in the management of patients with osteoporosis in a clinical setting?

Which of the following feedback mechanisms regulate the production of 1, 25(OH) 2D3?

"A progressive systemic skeletal disease characterized by low bone mass and micro architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptible to fracture" describes which of the following disorders?

A blood specimen is received in the laboratory from a maternity patient in the obstetric unit with blood magnesium ordered by the attending physician. The serum magnesium level is 5.0 mg/dL (RI = 1.6 - 2.6 mg/dL). Which of the following explains the elevated serum magnesium?

Biomarkers of bone formation include which of the following?

Which of the following laboratory results reflects a patient diagnosed with rickets as a result of a dietary deficiency of vitamin D?

Pyridinoline, carboxy, amino-terminal cross-linked telopeptide of type I collagen, and tartrate-resistant acid phosphatase are all examples of which of the following?

Which of the following is an example of a controllable preanalytical variable associated with specimen collection for bone biomarker testing?

Which of the following compounds promote osteoclast formation?

Heat inactivation and chemical inhibition are two methods used to measure which of the following analytes?

Blood levels of ionized calcium are sensitive to which of the following?

Which of the following do calcium, phosphorus, and magnesium have in common?

Monitoring intraoperative PTH is useful for:

Which of the following statements best illustrates the diagnostic criteria for primary hyperparathyroidism?

Which of the following instruments can measure calcium, magnesium, and phosphorus in blood samples?

Which of the following laboratory results best represents a patient with Paget's disease?

Which of the following reagents is used to determine the concentration of serum magnesium?

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Which of the following feedback mechanisms regulate the production of 1, 25(OH)₂D₃?