Module 3: Body Fluids and Electrolytes

Question 1

Reference range for Na+

Answer 1

130 - 150 mmol/L

Question 2

Reference range for K+

Answer 2

3.5 - 5.0 mmol/L

Question 3

Reference range for Cl-

Answer 3

98 - 108 mmol/L

Question 4

Reference range for HCO3-

Answer 4

22 - 30 mmol/L

Question 5

Reference range for total calcium

Answer 5

2.10 - 2.60 mmol/L

Question 6

Reference range for ionized calcium

Answer 6

1.15 - 1.35 mmol/L

Question 7

Methods for measuring calcium

Answer 7

Atomic absorption methods
O-cresolphthalein complexone method
Arsenazo III method (CX7 and Vitros)

Question 8

Methods for measuring Mg2+

Answer 8

Calmagite method
Formazan method (Vitros)
Methylthymol blue method
Enzymatic methods

Question 9

Methods for measuring phosphorous

Answer 9

Spectrophotometric methods (ammonium phosphomolybdate)

Question 10

Where is the thirst centre located in the brain?

Answer 10

The hypothalamus

Question 11

Another name for vasopressin

Answer 11

Anti-diuretic hormone

Question 12

Another name for anti-diuretic hormone

Answer 12

Vasopressin

Question 13

Major causes of hyponatremia

Answer 13

Hypoaldosteronism, severe diarrhea and vomiting, Addison’s disease, syndrome of inappropriate ADH secretion (SIADH)

Question 14

Major causes of hypokalemia

Answer 14

Prolonged diarrhea or vomiting, metabolic alkalosis, hyperaldosteronism

Question 15

Critical limits for sodium

Answer 15

Critical low: less than 125mmol/L

Critical high: more than 155mmol/L

Question 16

Ciritcal limits for potassium

Answer 16

Critical low: less than 2.5mmol/L

Critical high: more than 6.0mmol/L

Question 17

Critical limits for total calcium

Answer 17

Critical low: less than 1.75mmol/L

Critical high: more than 3.25mmol/L