NUR 201 EXAM 2 ELECTROLYTE MASTERY
GUIDE WITH HIGH-YIELD Q&A REVIEW
Electrolyte Exciters vs. Stabilizers
Q1. What are “electrolyte exciters”?
A: Electrolyte exciters are ions that increase the likelihood that a cell will fire an
action potential. When their levels rise, the cell membrane becomes more
excitable.
Key exciters: Potassium (K⁺) and Sodium (Na⁺).
Q2. What are “electrolyte stabilizers”?
A: Stabilizers are ions that decrease cell membrane excitability. Higher
concentrations make cells less likely to generate an action potential.
Key stabilizers: Calcium (Ca²⁺) and Magnesium (Mg²⁺).
Sodium Basics
Q3. What is the normal sodium range?
A: 135–145 mEq/L
Q4. What are the major functions of sodium in the body?
A:
,Primary cation in the extracellular fluid (ECF)
Regulates ECF osmolarity
Acts as an exciter aiding muscle contraction, cardiac conduction, and nerve
transmission
“Water follows sodium,” so Na⁺ affects fluid balance
Commonly paired with chloride or bicarbonate to maintain acid–base balance
When sodium is excreted, potassium is retained
Eliminated via urine, feces, and sweat
Controlled by thirst mechanism, ADH, glomerular filtration, RAAS, and natriuretic
peptides
Hyponatremia
Q5. What causes hyponatremia?
A: Two main mechanisms:
,1. Actual sodium loss:
Excess sweating
Diuretics
Wound drainage
Low aldosterone
Hyperlipidemia
Kidney disease
NPO status
Low-sodium diet
Hyperglycemia
2. Dilutional hyponatremia (relative Na⁺ deficit):
, Excess hypotonic fluids
Psychogenic polydipsia
Freshwater submersion
Renal failure
Hypotonic irrigations
SIADH
Heart failure
Drugs enhancing ADH activity
Q6. What symptoms occur in hyponatremia?
A:
Neurologic:
Brain swelling → ↑ ICP
GUIDE WITH HIGH-YIELD Q&A REVIEW
Electrolyte Exciters vs. Stabilizers
Q1. What are “electrolyte exciters”?
A: Electrolyte exciters are ions that increase the likelihood that a cell will fire an
action potential. When their levels rise, the cell membrane becomes more
excitable.
Key exciters: Potassium (K⁺) and Sodium (Na⁺).
Q2. What are “electrolyte stabilizers”?
A: Stabilizers are ions that decrease cell membrane excitability. Higher
concentrations make cells less likely to generate an action potential.
Key stabilizers: Calcium (Ca²⁺) and Magnesium (Mg²⁺).
Sodium Basics
Q3. What is the normal sodium range?
A: 135–145 mEq/L
Q4. What are the major functions of sodium in the body?
A:
,Primary cation in the extracellular fluid (ECF)
Regulates ECF osmolarity
Acts as an exciter aiding muscle contraction, cardiac conduction, and nerve
transmission
“Water follows sodium,” so Na⁺ affects fluid balance
Commonly paired with chloride or bicarbonate to maintain acid–base balance
When sodium is excreted, potassium is retained
Eliminated via urine, feces, and sweat
Controlled by thirst mechanism, ADH, glomerular filtration, RAAS, and natriuretic
peptides
Hyponatremia
Q5. What causes hyponatremia?
A: Two main mechanisms:
,1. Actual sodium loss:
Excess sweating
Diuretics
Wound drainage
Low aldosterone
Hyperlipidemia
Kidney disease
NPO status
Low-sodium diet
Hyperglycemia
2. Dilutional hyponatremia (relative Na⁺ deficit):
, Excess hypotonic fluids
Psychogenic polydipsia
Freshwater submersion
Renal failure
Hypotonic irrigations
SIADH
Heart failure
Drugs enhancing ADH activity
Q6. What symptoms occur in hyponatremia?
A:
Neurologic:
Brain swelling → ↑ ICP
