Exam II Acid/Base Balance, Electrolytes, Osmometer Flashcards Preview

MLT 130 Clinical Chemistry I > Exam II Acid/Base Balance, Electrolytes, Osmometer > Flashcards

Flashcards in Exam II Acid/Base Balance, Electrolytes, Osmometer Deck (71)
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1

Major intracellular cation
Normal value

Potassium
3.5-5.0 mM/L

2

Major extracellular cation
Normal Value

Sodium
136-145 mM/L

3

Major extracellular anion
Normal Value

Chloride
90-109 mM/L

4

What is the endpoint of mercurimetric chloride assay?

when excess Hg2+ forms a complex with an indicator like dyphenylcarbazon, producing a violet-blue color

5

What two cations are most likely to be ordered to determine the cause of cardiac tetany?

calcium
magnesium

6

calculate anion gap. be able to correlate abnormal anion gaps with other test results (such as BUN) or with instrument/tech errors

(Na + K)-(Cl + HCO3) = 12-20mmol/L
Na - (Cl + HCO3) = 8-18 mmol/L

7

What does %saturation refer to?
Normal value?

%saturation= serumFe/TIBC x 100
20-50%

8

What is hypokalemia?

low serum potassium
caused by dietary intake

9

If tetany is due to calcium, what specific fraction of calcium is involved?
Will it be increased or decreased?

Ionized(free) calcium
decreased

10

What analyte in the blood is used to measure serum phosphorous?
What is the normal value of serum phosphorous?

inorganic phosphorous
2.7-4.5 mg%

11

Why is it important to measure serum magnesium levels?

check for tetany due to magnesium deficiency

12

In analyzing calcium by atomic absorption, why is lanthanum added?

to prevent interference of phosphate

13

Calcium exist in serum as?
Which is physiologically active?

ionized(free) and protein bound
free

14

A patient with lactic acid acidosis would have an (increased/decreased) anion gap?

increased

15

What is the purpose of adding magnesium carbonate to an iron binding capacity?

to remove excess unbound iron

16

What does TIBC measure?

estimates transferrin level in serum

17

In what method is phosphate in serum combined with ammonium molybdate to form phosphomolybdate, which is then reduced to aminonapthosulfonic acid which is measured with spectrophotometery?

Fiske-Subbarow method for Phosphorus

18

Serum calcium and phosphorous have what kind of relationship?

reciprocal

19

What is the normal serum calcium level?

8.4-10.2 mg%

20

What would be the expected test results for calcium and phosphorus in hyperparathyroidism?

increase calcium
decrease phosphorus

21

What is the purpose of adding stannous chloride, ferrous sulfate, and ascorbic acid in the determination of inorganic phosphorus?

reducing agents

*reduces phosphomolybdate to aminonapthosulfonic acid

22

Name several things that can affect the level of circulating calcium

Vitamin D
serum protein levels
bone cell activity

23

What two hormones control serum calcium levels?

PTH and Calcitonin

*have an antagonistic relationship*

24

Which electrolyte is the chief plasma base that helps in maintaining osmotic pressure?

sodium

25

Hemolysis has the greatest effect on which serum levels?

potassium
magnesium

26

What is the function of aldosterone?

promotes sodium by kidneys, which results in increased water retention, blood vol and BP

27

What hormone has the most control over serum phosphate levels?

PTH

28

What is the normal serum osmolality?

275-295 mOsm/kg of H2O

29

What are the four main buffer systems in the body?

carbonic acid-bicarbonate system
hemoglobin buffers
other plasma proteins
phosphate-phosphoric acid system

30

The pKa of carbonic acid is?

6.1