Electrolytes

Question 1

Active Transport:

Answer 1

mechanism that requires energy to move ions across cellular membranes

Question 2

Electrolytes:

Answer 2

Ions capable of carrying an electric charge (anions or cations)

Question 3

Passive Transport:

Answer 3

passive movement of ions across a membrane (diffusion)

Question 4

Osmolality:

Answer 4

physical property of a solution that is based on the concentration of solutes per kg of solvent

Question 5

law of electroneutrality

Answer 5

Sum of all positive ions (cations) must equal the sum of negative ions (anions) to maintain electrical neutrality in the plasma.

Question 6

Sodium:

function, abundance, location, and regulation

Answer 6

Abundance: Most abundant Cation (90%)
Location: Extracellular (plasma)
Regulation:Kidney (conserves/excretes… RAAS)
Function: maintain osmotic pressure and water distribution (nerve/muscle impulses)

Question 7

Potassium:

function, abundance, location, and regulation

Answer 7

Abundance: Most abundant Intracellular cation
Location: Intracellular
Regulation: Kidney
Functions: regulate neuromuscular excitability and Contraction of heart
Intracellular fluid volume
H+ concentration

Question 8

Chloride:

function, abundance, location, and regulation

Answer 8

Abundance:Major extracellular anion
Location: Extracellular
Regulation:Ascending loop of henle / sweating
Functions: Maintain Osmotic pressure, hydration, electric neutrality

Question 9

CO2

function, abundance, location, and regulation

Answer 9

Abundance: 2nd most abundant extracellular anion
Location: Extracellular (plasma)
Regulation:Kidneys/Lungs
Function: blood buffering system

Question 10

Name the two main water compartments in the body and their constituents.

Answer 10

Extracellular Fluid: Fluid outside of the cells (plasma)
Sodium (Na)
Chloride (Cl)
Bicarbonate (HCO3

Intracellular Fluid: Fluid inside of the cells
Potassium (K)
Magnesium (Mg)

Question 11

Calculation for Anion Gap

Answer 11

Anion Gap (AG) = (Na + K) - (Cl + CO2)

Question 12

Normal Range of Anion Gap and significance of for discrepancies

Answer 12

High AG  (mult pts) =  analytical error
High AG (single pt) = 	possible metabolic issue
Low AG = 	analytic error

Question 13

What causes interference for measuring electrolytes?

Answer 13

Hemolysis

Question 14

Ion Selective Electrode for Sodium (Na)

Answer 14

Glass Ion Exchange Membrane

100x more sensitive for Na

Question 15

Ion Selective Electrode for Potassium (K)

Answer 15

Valinomycin Membrane

10000x more selective for K

Question 16

Ion Selective Electrode for Chloride (Cl)

Answer 16

Solid state Chloride electrode

Question 17

Ion Selective Electrode for CO2

Answer 17

glass pH electrode

(gas permeable silicone membrane)

Question 18

Flame Photometry

Answer 18

Electrolyte Quantification

Quantitate Na and K simultaneously
Internal Li Standard
Colorimetric reading at 525nm of red ferric thiocyanate complex
Acidification of sample converts to CO2 gas and measures

Question 19

Sodium: Normal & Critical Values

Answer 19

Normal: 135 – 145 mEq/L

Critical: < 120 mEq/L
> 155 mEq/L

Question 20

Potassium: Normal & Critical Values

Answer 20

Normal: 3.4 – 5.0 mEq/L

Critical: < 2.7 mEq/L

Question 21

Chloride: Normal & Critical Values

Answer 21

Normal: 95 – 110 mEq/L

Critical: < 85 mEq/L
> 115 mEq/L

Question 22

CO2: Normal Values

Answer 22

Normal: 23 – 29 mEq/L

Question 23

Anion Gap: Normal Value

Answer 23

10 – 20 mEq/L

Question 24

State the relationship between K+ and H+ in the body.

Answer 24

• K+ and H+ function towards blood buffering to ideally 7.4 pH
• Interference of K/H blood buffering leads to an acid/base imbalance

Question 25

Acidosis (metabolic)

Answer 25

1. Plasma H+ is High
2. H+ moves into cell to lower acidic blood buffering
3. K+ moves out of cell to maintain electroneutrality (Hyperkalemia)
4. Kidneys secrete H+ to maintain balance

Question 26

Alkalosis (metabolic)

Answer 26

1. Plasma H+ is Low
2. H+ moves from inside cells to plasma
3. K+ enters cells to remain electroneutrality (Hypokalemia)
4. Kidneys retain H+ ions