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Study Guide for Fluid and Electrolytes
1. What is homeostasis?
A. The way the body attempts to keep itself in a balanced physiologic state.
B. A balance of solvents and solutes for proper body functioning.
C. A balance of fluid and electrolytes to maintain proper body function.
D. The regulation of water and blood with other body substances.
2. Name five functions of water in the body:
1. Medium (solvent)
2. Transport
3. Lubricant
4. Insulator
5. Maintenance of body temperature
3. Identify the body fluids that fit the following descriptions:
Intracellular fluid
Interstitial fluid
Plasma or intravascular fluid
A. Fluid within cells; comprises about 60% of body fluids: Intracellular fluid
B. Contains a high level of potassium, and small amounts of sodium and chloride: Intracellular fluid
C. Fluid that is measured clinically (because of its accessibility): Plasma (intravascular fluid)
D. Extracellular fluids (ECF): Interstitial fluid and plasma (intravascular fluid)
4. Stanley, 32-years-old, weighs 180 pounds. His body weight contains about 108 pounds of fluid. This fluid includes 64.8 pounds of fluid within
cells (ICF) and 43.2 pounds of ECF. Most of his ECF is likely to be (plasma? interstitial fluid?).
5. Define the following terms:
Ion: dissociated particle of electrolyte
Electrolyte: substances that dissociate into electrically-charged particles that have the ability to carry an electric current
Cation: positively-charged ion (+)—has lost an electron
Anion: negatively-charged ion (-)—has gained an electron
Solvent: the liquid in which substances are dissolved
Solute: substance dissolved in a solution
Milliequivalent (mEq): chemical combining-power of the ion
Milligram (mg): weight of ions in solution
Gradient: difference in concentration, pressure, or electrical charge between two compartments
Passive transport: no ATP energy expended; flows with the concentration gradient
Active transport: ATP energy required: goes against concentration gradient
Equilibrium: equal concentrations on both sides of the membrane
Electroneutrality: total sum of cations must equal total sum of anions (pluses and minuses must equal)
6. Principle ions in Electrolyte balance (fill in)
ECF ions
ICF ions
–Sodium
Na+
–Potassium
K+
–Chloride
Cl–Magnesium Mg2+
–Bicarbonate
HCO3–Phosphate HPO42-
7. Complete this exercise about body fluids and electrolytes.
A. Circle the anion(s) in this list:
Bicarbonate Sodium Chloride Magnesium Glucose Phosphorus Potassium Protein Calcium
B. Circle the cation(s) in this list:
Bicarbonate Sodium Chloride Magnesium Glucose Phosphorus Potassium Protein Calcium
C. Which of the above is/are nonelectrolyte(s)? Glucose
8. What drives diffusion across a semipermeable membrane?
A. temperature
B. differences in solute concentration
C. differences in water concentration
D. reaction of water to form ions
E. affinity of membrane lipids for water
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9. Osmosis is
A. the pressure caused by solute concentration
B. the diffusion of water across a semipermeable membrane
C. the condition of having increased solute concentration on one side of a membrane
D. the result of mixing solute and water
E. a, c and d
10. Complete these statements about osmosis:
Complete these statements about osmosis:
A. water is moving down its concentration gradient
B. water is moving from the side of the membrane with the higher water concentration
C. water is moving to the side of the membrane with the higher solute concentration
D. the higher solute concentration is "pulling" water to its side of the membrane
11. Facilitated diffusion
A. occurs when small molecules pass through the lipid bilayer of a cell membrane
B. does not require protein channels or pores imbedded in the membrane to allow molecules to pass through
C. uses ATP for energy, but simple diffusion does not
D. is the method used to transport glucose across the cell membrane
E. moves against the concentration gradient
12. Which of the following is/ are true concerning active transport?
A. Flows with the gradient
B. Sodium-potassium pump is most common example
C. Moves “uphill”
D. Does not requires ATP
E. Uses carrier molecules
F. B, C, and E
G. A, D
13. Oxygen enters a cell via?
A. diffusion
B. osmosis
C. filtration
D. active transport
14. Choose the correct answers:
A.Hydrostatic pressure is a force that (pushes out of? pulls into?) blood vessels.
B. Colloidal osmotic pressure (COP) is a force that (pushes out of? pulls into) vessels.
15. There is a net movement of water across a selectively permeable membrane into a (an):
A. Hypotonic solution
B. Isotonic solution
C. Hypertonic solution
D. None of these—water does not move across selectively permeable membrane
16. In clients receiving 5% dextrose water intravenously, the nurse needs to be alert for which possible complication?
A. Cell swelling
B. Cerebral cell dehydration
C. Hypertension
D. Hypotension
17. Almost all of the osmotic pressure in extracellular fluids (ECF) is due to:
(1) Na+ and Cl(2) K+ and HCO3(3) BUN and glucose
18. A 0.9% NaCl solution is (hyper? iso? hypo?) tonic to human cells.
19. Human cells placed in hypertonic solutions are likely to (shrink? swell?).
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20. Jane Smith has a viral stomach flu with gastroenteritis and nausea, vomiting, watery diarrhea, fever, and body aches for the past 3 days. The
nurse knows that an isotonic solution is best given for severe dehydration and anticipates that which of the following will be ordered
A. D5/LR
B. 0.45 % NaCl
C. 3% NaCl
D. 0.9% NaCl
21. An IV solution of 3.0 NaCl will draw fluid from the
A. plasma into the interstitial space
B. intravascular space into the cells
C. cells and interstitium into the intravascular space
D. plasma into the cells
22. Indicate whether the following factors will cause the body to save or lose sodium by circling the correct answer:
A. The renin-angiotensin-aldosterone mechanism:
Save Na_
Lose Na_
No effect on Na_
B. ANP (atrial natriuretic peptide):
Save Na_
Lose Na_
No effect on Na_
C. ADH (antidiuretic hormone):
Save Na_
Lose Na_
No effect on Na_
23. List three important functions of sodium in the body.
Maintains ECF osmolarity (fluid balance)
Maintains ECF electroneutrality
Conducts action potentials in nerve/ muscle tissue (initiates skeletal muscle contractions)
Acid-base balance (sodium bicarbonate)
24. Visualize the hypothalamus when blood passing through it is slightly “thicker” or more concentrated than normal (increased serum osmolarity).
The hypothalamus then directs the posterior pituitary to secrete ADH, which has the following effects:
A. ADH stimulates kidney tubule cells to become (more? less?) permeable to water. In other words, ADH tells kidneys to “save the water!”
ADH (increases? decreases?) blood volume (blood becomes “less thick”) as urine output is (increased? decreased?).
ADH increases the permeability of the membrane to water and enhances free water reabsorption. Causes more water to be reabsorbed and returned to
the circulation, making the blood more dilute (reduced osmolarity of the blood). The urine will then be more concentrated.
B. The name antidiuretic hormone (ADH) indicates that its effects are (similar to? opposite of?) those of diuretics.
25. The main source of potassium each day is typically through diet. List several good sources of this electrolyte.
Fruits (avocados, raisins, cantaloupes, bananas, oranges)
Vegetables (spinach, mushrooms, potatoes, tomatoes)
26. Answer the following questions concerning potassium:
A. The hormone insulin facilitates movement of K+ (into? out of?) cells.
B. Metabolic acidosis facilitates movement of K+ (into? out of?) cells.
C. Severe exercise and cell trauma (including burns or excessive GI activity) move K+ (into? out of?) blood.
D. Aldosterone (increases? decreases?) tubular secretion of K+ into urine and thereby (increases? decreases?) serum potassium.
E. Addison’s disease has (deficient? excessive?) production of aldosterone. The patient with Addison's is more likely to develop (hypo? hype r?)
kalemia.
F. Sammy has lost much fluid during his prolonged diarrhea. He is at risk for hypokalemia.
G. Cushing’s syndrome (increases? decreases?) serum potassium.
27. As preparation for a barium enema, Mr. Brown has an order for tapwater enemas until clear. What would be the result, in terms of his electrolyte
balance, if Mr. Brown needed several of the enemas?
Dilutional hyponatremia
28. Mr. Bones has a serum calcium level of 7 mg/dL, as a result of acute pancreatitis. Describe the pathophysiologic changes for which you should
assess:
Tetany, positive Chvostek’s and Trousseau’s signs, paresthesias (tingling of lips and extremities), hyperreflexia, seizures, bleeding, increased
peristalsis (diarrhea)
29. Mr. B. Rittle has a serum calcium level of 12 mg/dL, as a result of metastatic bone cancer. Describe the pathophysiologic changes for which you
should assess:
Bone pain, fractures, polyuria, kidney stones, dehydration, blood clots, decreased peristalsis (constipation), hyporeflexia, confusion,
lethargy, coma
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30. Mr. Ed Dema has been receiving Furosemide (Lasix), a loop diuretic which causes potassium loss. His serum potassium level is 3.1 mEq/L.
What assessment findings would you expect?
Lethargy, leg cramps, muscle weakness, shallow respirations, irregular heart rate (dysrhythmias), hypoactive bowel sounds, nausea and
vomiting, flat T waves on ECG
31. Mrs. Seca is to receive 1000 ml of 5% dextrose in 0.45 NaCl with 40 mEq of potassium added. What precautions are indicated in administration
of her IV fluids?
Urinary output must be at least 30 ml/hr, IV site must be patent, proper dilution in IV fluid (20 mEq/250ml for peripheral IV site), no more
than 20 mEq/hr, must be run on a pump, double check serum lab values, NEVER IV push!
32. Compare calcium, phosphate, and magnesium by circling all correct answers in this exercise.
A. Serum level of 3.5 mg/dL is most normal for: Ca2+ Mg2+
PO43B. Renal failure is likely to cause high serum levels of: Ca2+ Mg2+
C. Malnutrition is likely to cause low levels of: Ca2+
PO43-
Mg2+ PO43-
D. Tetany and muscle spasms with positive Trousseau’s and Chvostek’s signs typically accompany low levels of:
Ca2+ Mg2+
PO43E. Lethargy or coma are likely to accompany high levels of: Ca2+ Mg2+ PO4333. Complete this exercise about phosphate (PO43-):
A. Most phosphate is located in (bones? serum?). Of the phosphate that is outside of bone, most is in (ICF? ECF?), so injury to cells is likely to
(increase? decrease?) serum levels of PO43-.
B. Normal serum phosphate levels are in the range of (3.0 to 4.5? 8.5 to 10.5?) mg/dL.
34. Write hyper or hypo next to causes of hyperphosphatemia or hypophosphatemia.
A. Chronic use of antacids with aluminum or calcium that bind phosphate: hypophosphatemia
B. Alcoholism (with associated malnutrition): hypophosphatemia
C. Phosphate-containing enemas: hyperphosphatemia
D. Massive trauma: hyperphosphatemia
E. Renal failure: hyperphosphatemia
35. List dietary sources of phosphate that can help to prevent and also treat hypophosphatemia.
milk and milk products, meat, fish, poultry, eggs, and peanuts
36. Circle the correct answer:
The effect of calcitonin is to (raise? lower?) serum calcium.
The effect of PTH is to (raise? lower?) serum calcium.
The effect of vitamin D is to (raise? lower?) serum calcium.
The effect of PTH is to (raise? lower?) serum phosphate.
The effect of vitamin D is to (raise? lower?) serum phosphate.
37. Which electrolyte imbalances are mainly the result of renal failure?
Hyperkalemia, hypermagnesemia, hypocalcemia, hyperphosphatemia
38. Which electrolytes have a large role in acid-base balance?
Bicarbonate, chloride, sodium, potassium, phosphorus
39. Both hyponatremia and hypernatremia can produce what symptoms?
LOC changes, confusion, seizures, coma
40. Both hypokalemia and hyperkalemia can cause:
Skeletal muscle weakness, paralysis, lethal cardiac dysrhythmias, cardiac arrest
41. Which electrolyte imbalances predispose to digoxin toxicity?
Hypokalemia, hypomagnesemia, hypercalcemia
42. What medications will contribute to hypokalemia?
Loop and thiazide diuretics (Lasix, Edecrin, HCTZ), laxatives and enemas (GoLitely, Kayexalate, Lactulose), corticosteroids, insulin
43. What medications will contribute to hyperkalemia?
Potassium supplements (K-Dur), potassium salt substitutes, ACE inhibitors, Aldactone, Augmentin, old blood transfusions