Question 1

Hypoparathyroidism is most commonly caused by:

Accepted Answer

A)  resistance to parathyroid hormone. 
B)  adenoma of the parathyroid gland. 
C)  pseudohypoparathyroidism. 
D)  parathyroid gland destruction. 
A)  resistance to parathyroid hormone. 
B)  adenoma of the parathyroid gland. 
C)  pseudohypoparathyroidism. 
D)  parathyroid gland destruction. D

Question 2

In a case of severe osteomalacia,would bone-specific alkaline phosphatase be increased,decreased,or remain unchanged?

Accepted Answer

A)  Increased 
B)  Decreased 
C)  Remain unchanged 
A)  Increased 
B)  Decreased 
C)  Remain unchanged A

Question 3

An individual's serum phosphate level is decreased but his physician cannot determine a physiological basis for this abnormal result.What could possibly have caused this result?

Accepted Answer

A)  Individual not fasting when blood was drawn 
B)  Specimen hemolysis 
C)  Use of IV carbohydrate therapy to stimulate insulin secretion 
D)  Diurnal variation 
A)  Individual not fasting when blood was drawn 
B)  Specimen hemolysis 
C)  Use of IV carbohydrate therapy to stimulate insulin secretion 
D)  Diurnal variation C

Question 4

Hypophosphatemia is seen in all of the following except:

Accepted Answer

A)  intravenous glucose administration. 
B)  vitamin D deficiency. 
C)  hyperparathyroidism. 
D)  malabsorption. 
A)  intravenous glucose administration. 
B)  vitamin D deficiency. 
C)  hyperparathyroidism. 
D)  malabsorption.

Question 5

Hypercalcemia occurs in humoral hypercalcemia of malignancy (HHM)because:

Accepted Answer

A)  tumors synthesize parathyroid hormone (PTH),which increases calcium levels in blood. 
B)  metastasizing cells synthesize calcium and release it into the circulation. 
C)  PTH-related protein (PTHrP)is synthesized by tumors and stimulates bone resorption. 
D)  osteoclasts bind tumor marker proteins and the process of bone remodeling becomes unregulated. 
A)  tumors synthesize parathyroid hormone (PTH),which increases calcium levels in blood. 
B)  metastasizing cells synthesize calcium and release it into the circulation. 
C)  PTH-related protein (PTHrP)is synthesized by tumors and stimulates bone resorption. 
D)  osteoclasts bind tumor marker proteins and the process of bone remodeling becomes unregulated.

Question 6

The clinical usefulness of calcitonin measurement is:

Accepted Answer

A)  in the assessment of primary hyperparathyroidism. 
B)  in the determination of sources of vitamin D deficiency. 
C)  the differential diagnosis of multiple endocrine neoplasia (MEN). 
D)  as a tumor marker for medullary thyroid carcinoma. 
A)  in the assessment of primary hyperparathyroidism. 
B)  in the determination of sources of vitamin D deficiency. 
C)  the differential diagnosis of multiple endocrine neoplasia (MEN). 
D)  as a tumor marker for medullary thyroid carcinoma.

Question 7

Pseudohypoparathyroidism is characterized by tissues that are resistant to the effects of circulating levels of parathyroid hormone (PTH).Which one of the following sets of values presents expected laboratory findings in this disorder?

Accepted Answer

A)  Calcium,phosphorus,and PTH within healthy reference intervals 
B)  Elevated calcium,decreased phosphorus,normal PTH 
C)  Decreased calcium,elevated phosphorus,elevated PTH 
D)  Elevated calcium,elevated phosphorus,decreased PTH 
A)  Calcium,phosphorus,and PTH within healthy reference intervals 
B)  Elevated calcium,decreased phosphorus,normal PTH 
C)  Decreased calcium,elevated phosphorus,elevated PTH 
D)  Elevated calcium,elevated phosphorus,decreased PTH

Question 8

An individual has the following laboratory test results: increased serum calcium,decreased serum phosphorus,increased parathyroid hormone.This individual most likely has:

Accepted Answer

A)  hyperparathyroidism. 
B)  hypoparathyroidism. 
C)  hyperthyroidism. 
D)  renal failure. 
A)  hyperparathyroidism. 
B)  hypoparathyroidism. 
C)  hyperthyroidism. 
D)  renal failure.

Question 9

A noncollagenous protein marker of bone formation that is released from bone during bone resorption,regulated by 1,25-dihydroxyvitamin D,and synthesized by osteoblasts and that regulates insulin secretion and sensitivity is:

Accepted Answer

A)  n-telopeptide. 
B)  deoxypyridinoline. 
C)  hydroxyproline. 
D)  osteocalcin. 
A)  n-telopeptide. 
B)  deoxypyridinoline. 
C)  hydroxyproline. 
D)  osteocalcin.

Question 10

Specimen requirements for assessing free calcium using ion-selective electrode methodology include:

Accepted Answer

A)  heparinized whole blood. 
B)  heparinized plasma. 
C)  serum. 
D)  all of the above. 
A)  heparinized whole blood. 
B)  heparinized plasma. 
C)  serum. 
D)  all of the above.

Question 11

What makes up the organic matrix component of bone?

Accepted Answer

A)  Calcium,protein,and collagen 
B)  Cells and collagen only 
C)  Minerals and cells only 
D)  Cells only 
A)  Calcium,protein,and collagen 
B)  Cells and collagen only 
C)  Minerals and cells only 
D)  Cells only

Question 12

A blood specimen is collected in a heparin-containing tube for calcium and magnesium determination.Upon centrifugation,the plasma appeared hemolyzed.How would this affect the magnesium value?

Accepted Answer

A)  There would be no effect on the magnesium value. 
B)  The magnesium would form complexes with the hemoglobin and the results would indicate a false negative value. 
C)  The magnesium would be incorporated into the bilirubin molecule,leading to a false negative value. 
D)  Because erythrocytes contain magnesium,hemolysis would increase its apparent value. 
A)  There would be no effect on the magnesium value. 
B)  The magnesium would form complexes with the hemoglobin and the results would indicate a false negative value. 
C)  The magnesium would be incorporated into the bilirubin molecule,leading to a false negative value. 
D)  Because erythrocytes contain magnesium,hemolysis would increase its apparent value.

Question 13

Telopeptides:

Accepted Answer

A)  are released from type I collagen during bone resorption. 
B)  are enzymes that become elevated during bone growth. 
C)  are proteins found in bone whose serum level can reflect bone formation. 
D)  is the most abundant noncollagenous protein in bone. 
A)  are released from type I collagen during bone resorption. 
B)  are enzymes that become elevated during bone growth. 
C)  are proteins found in bone whose serum level can reflect bone formation. 
D)  is the most abundant noncollagenous protein in bone.

Question 14

Which of the following is a recognized clinical feature of hypercalcemia?

Accepted Answer

A)  Muscle tetany 
B)  Muscle weakness 
C)  Dementia 
D)  Mental retardation 
A)  Muscle tetany 
B)  Muscle weakness 
C)  Dementia 
D)  Mental retardation

Question 15

The major cause of the decrease in total bone mass in an aging osteoporotic woman is:

Accepted Answer

A)  being postmenopausal and estrogen deficient. 
B)  lack of vitamin D. 
C)  severe hypocalcemia. 
D)  increased PTH. 
A)  being postmenopausal and estrogen deficient. 
B)  lack of vitamin D. 
C)  severe hypocalcemia. 
D)  increased PTH.

Question 16

The primary physiological regulator of parathyroid hormone (PTH)synthesis and secretion is:

Accepted Answer

A)  PTH releasing hormone from the pituitary gland. 
B)  the concentration of free calcium in blood or extracellular fluid. 
C)  the concentration of PTH in blood. 
D)  PTH stimulating hormone. 
A)  PTH releasing hormone from the pituitary gland. 
B)  the concentration of free calcium in blood or extracellular fluid. 
C)  the concentration of PTH in blood. 
D)  PTH stimulating hormone.

Question 17

Which one of the following diseases is characterized by a loss in bone mass?

Accepted Answer

A)  Osteoporosis 
B)  Osteomalacia 
C)  Rickets 
D)  Bone cancer 
A)  Osteoporosis 
B)  Osteomalacia 
C)  Rickets 
D)  Bone cancer

Question 18

Rickets is sometimes associated with deficiency of which one of the following vitamins?

Accepted Answer

A)  B12 
B)  A 
C)  D 
D)  C 
A)  B12 
B)  A 
C)  D 
D)  C

Question 19

Magnesium:

Accepted Answer

A)  concentration is present mostly in the complexed state. 
B)  decrease produces neuromuscular excitability. 
C)  is the second most abundant intracellular cation. 
D)  concentration is decreased with excessive intake of antacids. 
A)  concentration is present mostly in the complexed state. 
B)  decrease produces neuromuscular excitability. 
C)  is the second most abundant intracellular cation. 
D)  concentration is decreased with excessive intake of antacids.

Question 20

Which one of the following analytes is most useful in distinguishing primary from secondary hyperparathyroidism?

Accepted Answer

A)  Parathyroid hormone 
B)  Serum calcium 
C)  Vitamin D 
D)  Serum phosphorus 
A)  Parathyroid hormone 
B)  Serum calcium 
C)  Vitamin D 
D)  Serum phosphorus

Exam 39: Disorders of Bone and Mineral Metabolism

Hypoparathyroidism is most commonly caused by:

In a case of severe osteomalacia,would bone-specific alkaline phosphatase be increased,decreased,or remain unchanged?

An individual's serum phosphate level is decreased but his physician cannot determine a physiological basis for this abnormal result.What could possibly have caused this result?

Hypophosphatemia is seen in all of the following except:

Hypercalcemia occurs in humoral hypercalcemia of malignancy (HHM)because:

The clinical usefulness of calcitonin measurement is:

Pseudohypoparathyroidism is characterized by tissues that are resistant to the effects of circulating levels of parathyroid hormone (PTH).Which one of the following sets of values presents expected laboratory findings in this disorder?

An individual has the following laboratory test results: increased serum calcium,decreased serum phosphorus,increased parathyroid hormone.This individual most likely has:

A noncollagenous protein marker of bone formation that is released from bone during bone resorption,regulated by 1,25-dihydroxyvitamin D,and synthesized by osteoblasts and that regulates insulin secretion and sensitivity is:

Specimen requirements for assessing free calcium using ion-selective electrode methodology include:

What makes up the organic matrix component of bone?

A blood specimen is collected in a heparin-containing tube for calcium and magnesium determination.Upon centrifugation,the plasma appeared hemolyzed.How would this affect the magnesium value?

Telopeptides:

Which of the following is a recognized clinical feature of hypercalcemia?

The major cause of the decrease in total bone mass in an aging osteoporotic woman is:

The primary physiological regulator of parathyroid hormone (PTH)synthesis and secretion is:

Which one of the following diseases is characterized by a loss in bone mass?

Rickets is sometimes associated with deficiency of which one of the following vitamins?

Magnesium:

Which one of the following analytes is most useful in distinguishing primary from secondary hyperparathyroidism?

Clinical Chemistry, molecular Diagnostics, and Laboratory Medicine

Selection and Analytical Evaluation of Methodswith Statistical Techniques

Clinical Evaluation of Methods

Evidence-Based Laboratory Medicine

Establishment and Use of Reference Values

Specimen Collection, processing, and Other Preanalytical Variables

Quality Management

Principles of Basic Techniques and Laboratory Safety

Optical Techniques

Electrochemistry and Chemical Sensors

Electrophoresis

Chromatography

Mass Spectrometry

Enzyme and Rate Analyses

Immunochemical Techniques

Automation

Point-Of-Care Instrumentation

Amino Acids, peptides, and Proteins

Serum Enzymes

Tumor Markers and Cancer Genes

Kidney Function Test-Screatinine, Urea, and Uric Acid

Carbohydrates

Lipids, lip-Oproteins, apolipoproteins, and Other Cardiac Risk Factors

Electrolytes and Blood Gases

Hormones

Catecholamines and Serotonin

Vitamins, Trace Elements, and Nutritional Assessment

Hemoglobin, Iron, and Bilirubin

Porphyrins and Porphyrias

Therapeutic Drugs and Their Management

Clinical Toxicology

Toxic Metals

Diabetes

Cardiovascular Disease

Kidney Disease

Physiology and Disorders of Water,Electrolyte,and Acid-Base Metabolism

Liver Disease

Gastrointestinal and Pancreatic Diseases

Disorders of the Pituitary

Disorders of the Adrenal Cortex

Thyroid Disorders

Reproduction-Related Disorders

Pregnancy and Prenatal Testing

Newborn Screening and Inborn Errors of Metabolism

Pharmacogenetics

Principles of Molecular Biology

Nucleic Acid Techniques and Applications

Genomes and Nucleic Acid Alterations

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