ADULT HEALTH CJE EXAM
COMPREHENSIVE
STUDY GUIDE
SECTION 1: FLUID & ELECTROLYTE CONCEPTS
QUESTION 1
What is Osmolality?
ANSWER
The amount of particles within a fluid contributing to a fluid's concentration.
• High osmolality = Hypertonic solution
• Balanced osmolality = Isotonic solution
• Low osmolality = Hypotonic solution
RATIONALE / EXPLANATION
Osmolality determines how fluid moves between compartments. Normal serum osmolality is 275-
295 mOsm/kg. Understanding osmolality is essential for selecting appropriate IV fluids.
QUESTION 2
What is Hydrostatic Pressure?
ANSWER
A force pressing OUTWARD against a surface.
RATIONALE / EXPLANATION
Hydrostatic pressure pushes fluid out of capillaries into interstitial space. Increased hydrostatic
pressure (as in heart failure) causes edema.
QUESTION 3
What is Osmotic Pressure?
ANSWER
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,An INWARD pulling pressure towards a higher concentration.
RATIONALE / EXPLANATION
Osmotic pressure (oncotic pressure from proteins) pulls fluid back into capillaries. Low albumin =
low osmotic pressure = edema because fluid stays in tissues.
QUESTION 4
What is Diffusion?
ANSWER
Passive movement of particles DOWN a concentration gradient.
RATIONALE / EXPLANATION
Diffusion requires no energy - particles move from high to low concentration until equilibrium.
Example: oxygen diffusing from alveoli to blood.
QUESTION 5
What is Active Transport?
ANSWER
Using ENERGY to move electrolytes across cell membrane.
RATIONALE / EXPLANATION
Active transport moves particles against the concentration gradient (low to high). Example:
sodium-potassium pump uses ATP to move Na+ out and K+ into cells.
QUESTION 6
In what order does fluid move to the cell?
ANSWER
1. Vascular System
2. Capillary Membrane
3. Interstitial Area
4. Cell Membrane
RATIONALE / EXPLANATION
Understanding fluid movement helps explain edema formation and how IV fluids distribute
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, through the body's compartments.
QUESTION 7
What is an Osmolality Imbalance?
ANSWER
The blood is too CONCENTRATED or too DILUTE.
RATIONALE / EXPLANATION
High osmolality = dehydration/hypernatremia (too concentrated). Low osmolality = fluid
overload/hyponatremia (too dilute). Treatment depends on the underlying cause.
QUESTION 8
What labs measure Osmolality?
ANSWER
• Serum Osmolality - MOST ACCURATE!
• Urine Specific Gravity
• Hemoglobin & Hematocrit - higher Hct = higher osmolality
• Sodium levels - water follows salt! If sodium is elevated, osmolality is
elevated
RATIONALE / EXPLANATION
Multiple labs help assess fluid status. Hct rises with dehydration (hemoconcentration). Sodium is
the primary determinant of serum osmolality.
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COMPREHENSIVE
STUDY GUIDE
SECTION 1: FLUID & ELECTROLYTE CONCEPTS
QUESTION 1
What is Osmolality?
ANSWER
The amount of particles within a fluid contributing to a fluid's concentration.
• High osmolality = Hypertonic solution
• Balanced osmolality = Isotonic solution
• Low osmolality = Hypotonic solution
RATIONALE / EXPLANATION
Osmolality determines how fluid moves between compartments. Normal serum osmolality is 275-
295 mOsm/kg. Understanding osmolality is essential for selecting appropriate IV fluids.
QUESTION 2
What is Hydrostatic Pressure?
ANSWER
A force pressing OUTWARD against a surface.
RATIONALE / EXPLANATION
Hydrostatic pressure pushes fluid out of capillaries into interstitial space. Increased hydrostatic
pressure (as in heart failure) causes edema.
QUESTION 3
What is Osmotic Pressure?
ANSWER
Page 1 of 16
,An INWARD pulling pressure towards a higher concentration.
RATIONALE / EXPLANATION
Osmotic pressure (oncotic pressure from proteins) pulls fluid back into capillaries. Low albumin =
low osmotic pressure = edema because fluid stays in tissues.
QUESTION 4
What is Diffusion?
ANSWER
Passive movement of particles DOWN a concentration gradient.
RATIONALE / EXPLANATION
Diffusion requires no energy - particles move from high to low concentration until equilibrium.
Example: oxygen diffusing from alveoli to blood.
QUESTION 5
What is Active Transport?
ANSWER
Using ENERGY to move electrolytes across cell membrane.
RATIONALE / EXPLANATION
Active transport moves particles against the concentration gradient (low to high). Example:
sodium-potassium pump uses ATP to move Na+ out and K+ into cells.
QUESTION 6
In what order does fluid move to the cell?
ANSWER
1. Vascular System
2. Capillary Membrane
3. Interstitial Area
4. Cell Membrane
RATIONALE / EXPLANATION
Understanding fluid movement helps explain edema formation and how IV fluids distribute
Page 2 of 16
, through the body's compartments.
QUESTION 7
What is an Osmolality Imbalance?
ANSWER
The blood is too CONCENTRATED or too DILUTE.
RATIONALE / EXPLANATION
High osmolality = dehydration/hypernatremia (too concentrated). Low osmolality = fluid
overload/hyponatremia (too dilute). Treatment depends on the underlying cause.
QUESTION 8
What labs measure Osmolality?
ANSWER
• Serum Osmolality - MOST ACCURATE!
• Urine Specific Gravity
• Hemoglobin & Hematocrit - higher Hct = higher osmolality
• Sodium levels - water follows salt! If sodium is elevated, osmolality is
elevated
RATIONALE / EXPLANATION
Multiple labs help assess fluid status. Hct rises with dehydration (hemoconcentration). Sodium is
the primary determinant of serum osmolality.
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