Unit 4.2 Calcium Phosphate Magnesium

Question 1

What is the reference range for serum potassium?

Answer 1

3.5-5.5 mmol/L

Question 2

What is the reference range for plasma potassium in males?

Answer 2

3.5-4.5 mmol/L

Question 3

What is the reference range for plasma potassium in females?

Answer 3

3.4-4.4 mmol/L

Question 4

What is the normal range of potassium in 24-hour urine?

Answer 4

25-125 mmol/day

Question 5

What are the causes of hyperkalemia due to decreased renal excretion?

Answer 5

Renal failure, Addison’s disease (Hypoaldosteronism)

Question 6

What are the causes of hyperkalemia due to extracellular shift?

Answer 6

Acidosis, Muscle/cellular injury, Hemolysis

Question 7

What are the causes of hyperkalemia due to increased intake?

Answer 7

Oral or IV infusion

Question 8

What are the causes of pseudohyperkalemia?

Answer 8

Sample hemolysis, thrombocytosis, prolonged tourniquet application, excessive fist clenching, blood stored in ice, IV fluid, high blast counts

Question 9

What are symptoms of hypokalemia?

Answer 9

Muscular weakness, fatigue, muscle cramps, hypotension, decreased reflexes, palpitation, cardiac arrhythmias, cardiac arrest

Question 10

What plasma potassium level indicates hypokalemia?

Answer 10

Below 3.0 mmol/L

Question 11

What are the gastrointestinal causes of hypokalemia?

Answer 11

Diarrhea, vomiting

Question 12

What are the renal causes of hypokalemia?

Answer 12

Cushing’s syndrome, Hyperaldosteronism

Question 13

What are the causes of hypokalemia due to intracellular shift?

Answer 13

Alkalosis, Insulin overdose

Question 14

What is the most prevalent cation in the body?

Answer 14

Calcium

Question 15

What are the functions of calcium?

Answer 15

Bone mineralization, Blood coagulation, Neural transmission, Muscle contraction, Cardiac contractility and conduction, Hormonal secretion

Question 16

Which hormones promote calcium absorption?

Answer 16

Parathyroid Hormone (PTH), Vitamin D

Question 17

What hormone decreases calcium levels?

Answer 17

Calcitonin

Question 18

What is the reference method for total calcium determination?

Answer 18

Atomic Absorption Spectrophotometer

Question 19

What is the reference method for ionized calcium determination?

Answer 19

Ion Selective Electrode

Question 20

What is the reference range for total calcium in adults?

Answer 20

2.15-2.50 mmol/L or 8.6-10.0 mg/dL

Question 21

What is the reference range for ionized calcium in adults?

Answer 21

1.16-1.32 mmol/L or 4.6-5.3 mg/dL

Question 22

What are causes of hypercalcemia?

Answer 22

Primary hyperparathyroidism, Hyperthyroidism, Malignancy (PTH-rp), Multiple myeloma, Increased vitamin D, Thiazide diuretics, Prolonged immobilization

Question 23

What are causes of hypocalcemia?

Answer 23

Primary hypoparathyroidism, Hypomagnesemia, Hypermagnesemia, Hypoalbuminemia, Acute pancreatitis, Vitamin D deficiency, Renal disease, Rhabdomyolysis, Pseudohypoparathyroidism

Question 24

What is the 4th most abundant cation in the body?

Answer 24

Magnesium

Question 25

What are the functions of magnesium?

Answer 25

Cofactor of cellular enzymes, DNA replication and transcription, Cellular energy metabolism, Membrane stabilization, Ion transport, Nerve conduction

Question 26

Where is magnesium primarily stored?

Answer 26

Bones (53%)

Question 27

What hormone increases renal and intestinal magnesium reabsorption?

Answer 27

Parathyroid Hormone (PTH)

Question 28

What hormones increase renal excretion of magnesium?

Answer 28

Aldosterone, Thyroxine

Question 29

What is the reference method for total magnesium determination?

Answer 29

Atomic Absorption Spectrophotometer

Question 30

What is the reference range for serum magnesium?

Answer 30

0.63-1.0 mmol/L or 1.26-2.10 mEq/L

Question 31

What are causes of hypermagnesemia due to decreased excretion?

Answer 31

Acute/Chronic renal failure, Hypothyroidism, Hypoaldosteronism, Hypopituitarism

Question 32

What are causes of hypermagnesemia due to increased intake?

Answer 32

Antacids, Enemas, Cathartics, Therapeutic use (eclampsia, cardiac arrhythmia)

Question 33

What are causes of hypomagnesemia due to reduced intake?

Answer 33

Poor diet, prolonged magnesium-deficient IV therapy, chronic alcoholism

Question 34

What are causes of hypomagnesemia due to decreased absorption?

Answer 34

Malabsorption syndrome, surgical resection of small intestine, pancreatitis, vomiting, diarrhea, laxative abuse, neonatal hypomagnesemia

Question 35

What is the predominant intracellular anion?

Answer 35

Phosphorus

Question 36

What are functions of phosphorus?

Answer 36

Component of DNA and RNA, Energy reservoir (ATP), Regulated by PTH, Vitamin D, and Growth Hormone

Question 37

What is the reference range for serum phosphorus in adults?

Answer 37

0.78-1.42 mmol/L or 2.4-4.4 mg/dL

Question 38

What is the reference range for urine phosphorus (24h)?

Answer 38

13-42 mmol/day or 0.4-1.3 g/day

Question 39

What are causes of hyperphosphatemia?

Answer 39

Severe kidney dysfunction, Hypoparathyroidism, Pseudohypoparathyroidism, Diabetic ketoacidosis, Crush injuries, Rhabdomyolysis, Sepsis, Large phosphate intake

Question 40

What are causes of acute hypophosphatemia?

Answer 40

Severe undernutrition, Diabetic ketoacidosis, Severe alcoholism, Severe burns

Question 41

What are causes of chronic hypophosphatemia?

Answer 41

Hyperparathyroidism, Chronic diarrhea, Long-term diuretic use, Excessive aluminum-containing antacids, Theophylline use