Chapter 12: Solutions, Body Fluids, and Electrolytes
Test Bank
MULTIPLE CHOICE
1. What is a uniform distribution of large molecules that attract and hold water?
a. colloid
b. mixture
c. solution
d. suspension
ANS: A
Colloids (sometimes called dispersions or gels) consist of large molecules that attract and hold
water
DIF: Application
REF: p. 273
OBJ: 1
2. The combination of red blood cells in plasma is a good example of what?
a. colloid
b. mixture
c. solution
d. suspension
ANS: D
Red blood cells in plasma are an example of a suspension.
DIF: Application
REF: p. 273
OBJ: 1
3. What is a stable mixture of two or more evenly dispersed substances?
a. colloid
b. mixture
c. solution
d. suspension
ANS: C
A solution is a stable mixture of two or more substances in a single phase. One substance is
evenly dispersed throughout the other.
DIF: Application
REF: p. 273
OBJ: 1
4. The ease with which a gas dissolves into a solvent is at least partially determined by which of
the following?
a. gas conductivity
b. gas temperature
c. level of 2,3-DPG
d. solvent conductivity
ANS: B
The ease with which a solute dissolves in a solvent is its solubility, which is influenced by
five factors:
1. Nature of the solute. The ease with which substances go into a solution in a given solvent
depends on the forces of the solute-solute molecules and varies widely.
2. Nature of the solvent. A solvent’s ability to dissolve a solute depends on the bonds of the
solvent-solvent molecules, and also varies widely.
3. Temperature. Solubility of most solids increases with increased temperature. However, the
solubility of gases varies inversely with temperature.
4. Pressure. The solubility of solids and liquids is not greatly affected by pressure. The
solubility of gases in liquids, however, varies directly with pressure.
5. Concentration. The concentration of a solute or available solvent will have an effect of how
much of the substance goes into solution.
DIF: Application
REF: p. 273
OBJ: 2
5. Which of the following is NOT true regarding solubility?
a. Gas solubility varies directly with pressure.
b. Gas solubility varies directly with temperature.
c. Solvents vary in their ability to dissolve substances.
d. The solubility of solids increases with temperature.
ANS: A
The ease with which a solute dissolves in a solvent is its solubility, which is influenced by
five factors:
1. Nature of the solute. The ease with which substances go into a solution in a given solvent
depends on the forces of the solute-solute molecules and varies widely.
2. Nature of the solvent. A solvent’s ability to dissolve a solute depends on the bonds of the
solvent-solvent molecules, and also varies widely.
3. Temperature. Solubility of most solids increases with increased temperature. However, the
solubility of gases varies inversely with temperature.
4. Pressure. The solubility of solids and liquids is not greatly affected by pressure. The
solubility of gases in liquids, however, varies directly with pressure.
5. Concentration. The concentration of a solute or available solvent will have an effect of how
much of the substance goes into solution.
DIF: Application
REF: p. 273
OBJ: 2
6. Gas transport in the body is most affected by changes in which of the following variables?
a. ambient pressure
b. inspired gas temperature
c. oxygen’s solubility coefficient
d. water vapor pressure of inspired gases
ANS: A
The partial pressure of the dissolved gas is the product of its coefficient of solubility and the
partial pressure of the gas to which the liquid is exposed. Oxygen and carbon dioxide
transport can change significantly with changes in body temperature or the pressure to which
the body is exposed.
DIF: Application
REF: p. 273
OBJ: 2
7. A solution holding the maximum amount of solute in a given volume at a constant
temperature is said to be what?
a.
b.
c.
d.
hypertonic
hypotonic
saturated
supersaturated
ANS: C
A saturated solution has the maximal amount of solute that can be held in a given volume of a
solvent at a constant temperature.
DIF: Application
REF: p. 273
OBJ: 2
8. The most important physiological characteristic of solutions is their ability to exert pressure.
a. True
b. False
ANS: A
The most important physiologic characteristic of solutions is their ability to exert pressure.
DIF: Application
REF: p. 274
OBJ: 1
9. What is the attractive force of solute particles in a concentrated solution?
a. diffusion pressure
b. gas pressure
c. hydrostatic pressure
d. osmotic pressure
ANS: D
Osmotic pressure is the force produced by solvent particles under certain conditions.
If a solution is placed on one side of a semipermeable membrane and pure solvent on the
other, solvent molecules will move through the membrane into the solution. The force driving
solvent molecules through the membrane is osmotic pressure (Figure 12-2, A).
DIF: Recall
REF: p. 274
OBJ: 3
10. What is the effect of osmotic pressure on solutions of different solute concentrations,
separated by a semipermeable membrane?
a. causes a net loss of fluid
b. equal distribution of solvent
c. has no effect in this situation
d. redistribution of the solute
ANS: B
Osmotic pressure tries to distribute solvent molecules so that the same concentration exists on
both sides of the membrane.
DIF: Application
REF: p. 274
OBJ: 3
11. If a 60% solution (A) were exposed to a 10% solution (B) across a semipermeable membrane,
what would be the strength of each solution following equilibrium?
a. solution A 10%/solution B 60%
b. solution A 35%/solution B 35%
c. solution A 50%/solution B 20%
d. solution A 60%/solution B 10%
ANS: B
Osmotic pressure can also be visualized as an attractive force of solute particles in a
concentrated solution. If 100 ml of a 50% solution is placed on one side of a membrane and
100 ml of a 30% solution is placed on the other side, solvent molecules will move from the
dilute to the concentrated side (Figure 12-2, D and E). The particles in the concentrated
solution attract solvent molecules from the dilute solution until equilibrium occurs.
Equilibrium exists when the concentrations (i.e., ratio of solute to solvent) in both
compartments are equal (40% in Figure 12-2).
DIF: Application
REF: p. 274
OBJ: 3
12. Which of the following is true regarding osmotic pressure?
a. Osmotic pressure depends on the number of particles in solution.
b. Osmotic pressure varies inversely with temperature.
c. Osmotic pressure is highest in dilute solutions.
d. Osmotic pressure varies inversely with tonicity.
ANS: A
Osmotic pressure depends on the number of particles in solution but not on their charge or
identity. A 2% solution has twice the osmotic pressure of a 1% solution under similar
pressures. For a given amount of solute, osmotic pressure is inversely proportional to the
volume of solvent. Osmotic pressure varies directly with temperature, increasing by 1/273 for
each 1° C.
DIF: Application
REF: p. 274
OBJ: 3
13. Which of the following is an isotonic solution?
a. 0.09% NaCl
b. 0.90% NaCl
c. 9.00% NaCl
d. 19.0% NaCl
ANS: B
Average body cellular fluid has a tonicity equal to a 0.9% solution of sodium chloride (NaCl;
sometimes referred to as physiologic saline). Solutions with similar tonicity are called
isotonic.
DIF: Recall
REF: p. 275
OBJ: 3
14. A 3% NaCl solution is called what?
a. hypertonic
b. hypotonic
c. isotonic
d. normotonic
ANS: B
Those solutions with more tonicity are hypertonic, and those solutions with less tonicity are
hypotonic.
DIF: Application
REF: p. 275
OBJ: 3
15. If your objective were to draw water out of cells or tissues, you would expose them to what
type of solution?
a. hypertonic
b. hypotonic
c. isotonic
d. normotonic
ANS: A
Hypertonic solutions draw water out of cells.
DIF: Application
REF: p. 275
OBJ: 3
16. Which of the following is termed a physiologic solution?
a. isotonic
b. noncovalent
c. nonpolar covalent
d. polar electrovalent
ANS: C
In electrochemical terms, there are three basic types of physiologic solutions. Depending on
the solute, solutions are ionic (electrovalent), polar covalent, or nonpolar covalent.
DIF: Recall
REF: p. 275
OBJ: 5
17. Positive ions are referred to as what?
a. anions
b. cations
c. covalents
d. electrolytes
ANS: B
If an electrode is placed in such a solution, positive ions migrate to the negative pole of the
electrode. These ions are called cations.
DIF: Recall
REF: p. 275
OBJ: 5
18. In which of the following solutions do the molecules of solute remain intact?
a. electrolytic
b. electrovalent
c. nonpolar covalent
d. polar covalent
ANS: C
In nonpolar covalent solutions, molecules of solute remain intact and do not carry electrical
charges; these solutions are referred to as nonelectrolytes.
DIF: Application
REF: p. 275
OBJ: 5
19. How is the gram-equivalent (gEq) weight of a substance computed?
a. dividing its gram atomic weight by its valence
b. dividing its valence by its gram atomic weight
c. multiplying its atomic number times its atomic weight
d. multiplying its gram atomic weight times its valence
ANS: A
Gram equivalent weight values. A gEq of a substance is calculated as its gram atomic
(formula) weight divided by its valence. The valence signs (+ or –) are disregarded.
DIF: Analysis
REF: p. 276
OBJ: 1
20. What is the gEq weight of an acid?
a. amount of the acid containing 1 mol of replaceable H+ ions
b. amount of the acid containing 1 mol of replaceable OH– ions
c. gram atomic weight of the acid times its valence
d. milligrams of acid per deciliter (dl) of normal solution
ANS: A
The gram equivalent weight of an acid may be calculated by dividing its gram formula weight
by the number of hydrogen atoms in its formula, as shown in the following reaction:
The single H+ of hydrochloric acid (HCl) is replaced by Na+. One mole of HCl has 1 mole of
replaceable hydrogen. By definition, the gEq of HCl must be the same as its gram formula
weight, or 36.5 g.
DIF: Application
REF: p. 276
OBJ: 1
21. A serum value of 140 mEq/L of Na is equivalent to how many mg/dl?
a. 14 mg/dl
b. 70 mg/dl
c. 280 mg/dl
d. 322 mg/dl
ANS: D
For example, to convert a serum Na+ value of 322 mg/dl to mEq/L, the equation is used as
follows:
DIF: Analysis
REF: p. 276
OBJ: 1
22. In which of the following types of solutions is the relationship of solute to solvent expressed
as a proportion?
a. normal
b. percent
c. ratio
d. weight/volume
ANS: C
Ratio solution. The amount of solute to solvent is expressed as a proportion.
DIF: Application
REF: p. 277
OBJ: 4
23. You prepare a solution by dissolving 5 g of glucose in 100 ml of solution. What type of
solution are you making?
a. normal
b. percent
c. ratio
d. weight/volume
ANS: D
It is defined as weight of solute per volume of solution. This method is sometimes erroneously
described as a percent solution. W/V solutions are commonly expressed in grams of solute per
100 ml of solution. For example, 5 g of glucose dissolved in 100 ml of solution is properly
called a 5% solution.
DIF: Application
REF: p. 280
OBJ: 4
24. You prepare a solution by combining 5 g of glucose with 95 g of water. What type of solution
are you making?
a. normal
b. percent
c. ratio
d. weight/volume
ANS: B
Percent solution. A percent solution is weight of solute per weight of solution. Five grams of
glucose dissolved in 95 g of water is a true percent solution. The glucose is 5% of the total
solution weight of 100 g.
DIF: Application
REF: p. 278
OBJ: 4
25. What type of solution could have 1 mol of solute per L of solution?
a. molal
b. molar
c. normal
d. weight/volume
ANS: B
Molar solution. A molar solution has 1 mole of solute per liter of solution, or 1 mmol/ml of
solution. Solute is measured into a container, and solvent is added to produce the solution
volume desired.
DIF: Application
REF: p. 278
OBJ: 1
26. What type of solution could have 1 gEq of solute per L of solution?
a. molal
b. molar
c. normal
d. weight/volume
ANS: C
Normal solution. A normal solution has 1 gEq of solute per liter of solution, or 1 mEq/ml of
solution.
DIF: Application
REF: p. 278
OBJ: 1
27. You add 50 ml of water to 150 ml of a 6% solution. What is the new concentration?
a. 3.0%
b. 4.5%
c. 7.5%
d. 12.0%
ANS: B
If 50 ml of water is added to 150 ml of a 3% (0.03) solution, the new concentration is
calculated by rearranging the dilution equation to find C2 as follows:
DIF: Analysis
REF: p. 278
OBJ: 4
28. What is a characteristic of an acid?
a. absorbs H+ ions
b. accepts a proton
c. is a proton donor
d. produces OH– ions
ANS: C
Another definition of an acid is that of Brönsted-Lowry, in which an acid is any compound
that is a proton (H+) donor.
DIF: Recall
REF: p. 279
OBJ: 5
29. Supply the definition for a base substance.
a. compound that will donate a H+ ion
b. any compound that will accept a proton
c. only substances that contain a hydroxyl group
d. substances that contain Na+ ions
ANS: B
The Brönsted-Lowry definition of a base is any compound that accepts a proton.
DIF: Recall
REF: p. 279
OBJ: 5
30. Which of following is NOT a nonhydroxide base?
a. ammonia
b. carbonates
c. certain proteins
d. ammonium
ANS: D
Nonhydroxide bases. Ammonia and carbonates are good examples of nonhydroxide bases.
Proteins, with their amino groups, also can serve as nonhydroxide bases.
DIF: Recall
REF: p. 279
OBJ: 5
31. Where does ammonia play its most important role as a base buffer?
a. kidney
b. liver
c. lung
d. vasculature
ANS: A
Ammonia plays an important role in renal excretion of acid.
DIF: Recall
REF: p. 279
OBJ: 5
32. Which of the following is a facet of blood proteins?
a. Blood proteins are composed of amino acids held together by fatty acids.
b. Deoxygenated hemoglobin (Hb) is unable to accept H+ ions.
c. In an alkaline environment, blood proteins can act as bases.
d. The imidazole group on amino acids is the key binding site for other amino acids.
ANS: C
Protein bases. Proteins are composed of amino acids bound together by peptide links.
Physiologic reactions in the body occur in a mildly alkaline environment. This allows proteins
to act as H+ receptors, or bases. Cellular and blood proteins acting as bases are transcribed as
prot–. The imidazole group of the amino acid histidine is an example of an H+ acceptor on a
protein molecule (Figure 12-4). The ability of proteins to accept hydrogen ions limits H+
activity in solution, which is called buffering. The ability of hemoglobin to accept (i.e., buffer)
H+ ions depends on its oxygenation state. Deoxygenated (reduced) hemoglobin is a stronger
base (i.e., a better H+ acceptor) than oxygenated hemoglobin.
DIF: Application
REF: p. 279
OBJ: 6
33. Pick the correct statement as it relates to hemoglobin and acid-base buffering.
a. Deoxygenated hemoglobin acts as an acid at the tissue level.
b. Deoxygenated hemoglobin is a fairly strong base.
c. Hemoglobin contributes more H+ in the face of increased histidine.
d. In an alkaline environment, hemoglobin becomes an ineffective base.
ANS: B
The ability of proteins to accept hydrogen ions limits H+ activity in solution, which is called
buffering. The ability of hemoglobin to accept (i.e., buffer) H+ ions depends on its
oxygenation state. Deoxygenated (reduced) hemoglobin is a stronger base (i.e., a better H+
acceptor) than oxygenated hemoglobin.
DIF: Application
REF: p. 280
OBJ: 6
34. What is the relation between pure water and acid-base balance?
a. A solution with an OH– concentration greater than that of water acts as an acid.
b. Pure water is slightly acidic solution.
c. The concentrations of both H+ and OH– ions are equal.
d. The H+ concentration of water can be designated as 1 nmol/L.
ANS: C
The concentration of both H+ and OH– in pure water is 107 mol/L.
DIF: Application
REF: p. 280
OBJ: 7
35. How is pH defined?
a. log of the dissociation constant of the weak acid in a solution
b. negative logarithm of the H+ ion concentration of a solution
c. point at which an electrolyte solution is exactly 50% dissociated
d. ratio of a solution’s weak acid concentration to its conjugate base pair
ANS: B
pH is the negative logarithm of the [H+] used as a positive number.
DIF: Application
REF: p. 280
OBJ: 7
36. Which of the following describes an aspect of pH?
a. Any solution with a pH of 7 is neutral.
b. A pH of 7 describes an acidotic solution.
c. A pH change from 7 to 8 equals a 2-fold increase in H+ ion concentration.
d. The pH is the log of the OH- ion concentration.
ANS: A
In this scheme, any solution with a pH of 7.00 is neutral, corresponding to the [H+] of pure
water.
DIF: Application
REF: p. 281
OBJ: 7
37. If a patient’s pH were to drop from 7.40 to 7.10, the H+ concentration will increase by how
much?
a. 2
b. 3
c. 5
d. 10
ANS: A
Similarly, a change in pH of 0.3 unit equals a 2-fold change in [H+].
DIF: Analysis
REF: p. 281
OBJ: 7
38. Which of the following are true regarding water in the human body?
1. The more fatty tissue there is, the greater is the percentage of body water.
2. Total body water depends on an individual’s weight and sex.
3. Water constitutes about 45% to 80% of an individual’s body weight.
4. Water content is highest in the aged.
a.
b.
c.
d.
1 and 2
2 and 4
3 and 4
2 and 3
ANS: D
Water is a major component of the body. It makes up 45% to 80% of an individual’s body
weight, depending on that person’s weight, gender, and age. Leanness is associated with
higher body water content. Obese individuals have a lower percentage of body water (as much
as 30% less) than do normal-weight individuals. Men have a slightly higher percentage of
total body water than women have. Total percentage of body water in infants and children is
substantially greater than it is in adults. In the newborn, water accounts for 80% of the total
body weight.
DIF: Application
REF: p. 281
OBJ: 8
39. Intracellular water represents about what proportion of total body water?
a.
b.
c.
d.
ANS: D
Intracellular water accounts for approximately two thirds of the total body water, and
extracellular water accounts for the remaining third.
DIF: Recall
REF: p. 281
OBJ: 8
40. What is the smallest fluid subcompartment of extracellular water?
a. interstitial
b. intraorganelle
c. intravascular
d. transcellular
ANS: D
Extracellular water is found in three subcompartments: (1) intravascular water (plasma), (2)
interstitial water, and (3) transcellular fluid. Intravascular water makes up approximately 5%
of the body weight. Interstitial water is water in the tissues between the cells. It makes up
approximately 15% of the body weight. Transcellular fluid is quite small in proportion to
plasma and interstitial fluid.
DIF: Application
REF: p. 281
OBJ: 8
41. Which of the following is NOT a major extracellular electrolyte?
a. Cl
b. HCO3
c. K+
d. Na+
ANS: C
Sodium (Na+), chloride (Cl–), and bicarbonate (HCO3–) are predominantly extracellular
electrolytes.
DIF: Recall
REF: p. 282
OBJ: 8
42. What are the main intracellular electrolytes?
1. K+
2. Na+
3. Phosphate
4. Sulfate
a. 1, 3, and 4
b. 2, 3, and 4
c. 1 and 2
d. 1, 2, 3, and 4
ANS: A
Potassium (K+), magnesium (Mg2+), phosphate (PO43–), sulfate (SO42–), and protein constitute
the main intracellular electrolytes.
DIF: Recall
REF: p. 282
OBJ: 8
43. Which of the following is FALSE regarding body fluids and electrolytes?
a. Interstitial fluid contains substantially more protein than does plasma.
b. Intravascular and interstitial fluid have similar electrolyte compositions.
c. Osmotic pressure helps to determine fluid distribution between compartments.
d. Proteins account for the high colloid osmotic pressure of plasma.
ANS: A
Intravascular and interstitial fluids have similar electrolyte compositions. However, plasma
contains substantially more protein than interstitial fluid. Proteins, chiefly albumin, account
for the high osmotic pressure of plasma. Osmotic pressure is an important determinant of fluid
distribution between vascular and interstitial compartments.
DIF: Application
REF: p. 282
OBJ: 8
44. What maintains the volume and composition of body fluids?
1. filtration and reabsorption of sodium by the kidneys
2. regulation of water balance by vasopressin (ADH)
3. gastrointestinal filtration and excretion of chloride
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 1, 2, and 3
ANS: A
The kidneys maintain the volume and composition of body fluids by two related mechanisms.
First, filtration and reabsorption of sodium adjust urinary sodium excretion to match changes
in dietary intake. Second, water excretion is regulated by secretion of antidiuretic hormone
(ADH, or vasopressin).
DIF: Application
REF: p. 282
OBJ: 8
45. Water can be lost from the body through what organ systems?
1. gastrointestinal tract
2. liver
3. lungs
4. skin
a. 1, 2, and 3
b. 1, 3, and 4
c. 2 and 4
d. 1, 2, 3, and 4
ANS: B
Water may be lost from the body through the skin, lungs, kidneys, and gastrointestinal tract.
DIF: Application
REF: p. 282
OBJ: 9
46. Insensible water loss occurs through what organs?
1. gastrointestinal tract
2. kidneys
3. lungs
4. skin
a. 3 and 4
b. 1, 2, and 4
c. 2 and 3
d. 2 and 4
ANS: A
Water loss can be insensible, such as vaporization of water from the skin and lungs.
DIF: Application
REF: p. 282
OBJ: 9
47. An adult’s insensible water loss averages what level?
a. 300 ml/day
b. 500 ml/day
c. 700 ml/day
d. 900 ml/day
ANS: D
See Table 12-4.
DIF: Recall
REF: p. 282
OBJ: 9
48. An adult’s insensible water through the lungs averages what level?
a. 100 ml/day
b. 200 ml/day
c. 300 ml/day
d. 400 ml/day
ANS: B
See Table 12-4.
DIF: Recall
REF: p. 282
OBJ: 9
49. What is the average urine output in a healthy adult?
a. 600 to 800 ml/day
b. 800 to 1000 ml/day
c. 1000 to 1200 ml/day
d. 1200 to 1400 ml/day
ANS: C
See Table 12-4.
DIF: Recall
REF: p. 282
OBJ: 9
50. Which of the following is FALSE regarding water balance and the gastrointestinal tract?
a. The gastrointestinal tract processes some 8 to 10 L of fluid per day.
b. The large intestine reclaims more than 98% of the daily gastrointestinal fluid
volume.
c. Vomiting and diarrhea can cause large gastrointestinal tract fluid losses.
d. The gastrointestinal tract is responsible for the most sensible fluid loss.
ANS: D
The gastrointestinal tract manufactures 8 to 10 L of fluid per day. More than 98% of this
volume is reclaimed in the large intestine. In patients who are vomiting or have diarrhea,
water losses through the gastrointestinal tract can be considerable. Individuals with severe
burns or open wounds can also lose large quantities of water.
DIF: Application
REF: p. 282
OBJ: 9
51. Patients with what condition are prone to evaporative water loss through the lungs?
1. artificial airways
2. hypothermia
3. increased ventilation
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 1, 2, and 3
ANS: B
Patients with increased ventilation also have increased water losses through increased
evaporation from the respiratory tract. Patients with artificial airways are prone to evaporative
water loss if inspired air is not adequately humidified. Artificial airways bypass the normal
heat and water exchange processes of the nose.
DIF: Application
REF: p. 282
OBJ: 9
52. Pick the statement that best describes the relationship between infants and their body fluids?
a. Fluid loss or lack of intake depletes infants of water slower than it does adults.
b. Infants have proportionately less body water than do adults.
c. Infants’ higher metabolic rates necessitate greater urinary excretion compared with
adults.
d. Under normal circumstances, infants’ water loses are three times those of adults.
ANS: C
Infants have a greater proportion of body water than do adults, particularly in the extracellular
compartments (Table 12-3). Water loss in infants may be twice that of adults. Infants also
have a greater body surface area (in proportion to body volume) than adults, making their
basal heat production twice as high. Higher metabolic rates in infants necessitate greater
urinary excretion. Infants turn over approximately half of their extracellular fluid volume
daily; adults turn over approximately one seventh. Fluid loss or lack of intake can rapidly
deplete an infant of water.
DIF: Application
REF: p. 282-283
OBJ: 9
53. By what process is water replenished?
1. absorption
2. ingestion
3. metabolism
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 1, 2, and 3
ANS: C
Water is replenished in two major ways: ingestion and metabolism.
DIF: Application
REF: p. 283
OBJ: 9
54. During recovery from a serious surgery or trauma, how much water is likely to be produced in
a 24-hour period by the catabolism of fat and proteins?
a. 300 ml
b. 500 ml
c. 750 ml
d. 1000 ml
ANS: D
Recovery after surgery or trauma may be similar to starvation. Under such conditions,
approximately 500 mg of protein and a similar amount of fat are metabolized. This yields
approximately 1 L of water/day.
DIF: Recall
REF: p. 283
OBJ: 9
55. What best describes an aspect of the movement of fluid and solutes between the capillaries
and the interstitial space?
a. At the tissue level, osmotic pressure tends to draw water into the interstitial space.
b. Electrolytes move freely across the capillary wall into the interstitium.
c. The capillary and interstitial hydrostatic pressures are approximately equal.
d. The interstitial fluid has a relatively high protein concentration.
ANS: B
The first stage of homeostasis is fluid exchange between systemic capillaries and interstitial
fluid by passive diffusion. Capillary walls are permeable to crystalline electrolytes. This
allows equilibrium between the two extracellular compartments to occur quickly.
DIF: Application
REF: p. 283
OBJ: 10
56. What is the net effect of the hydrostatic pressure gradient between the capillary and interstitial
space?
a. It tends to push water into the capillaries.
b. It tends to push water into the interstitial spaces.
c. The pressure gradient is zero so fluid movement is due to osmosis.
d. It tends to push water into the cells.
ANS: B
Movement of fluid and solutes from capillary blood to interstitial spaces is enhanced by the
difference in hydrostatic pressure between compartments. Hydrostatic pressure difference
depends on blood pressure, blood volume, and the vertical distance of the capillary from the
heart (i.e., the effects of gravity). Hydrostatic pressure tends to cause fluid to leak out of
capillaries into the interstitial spaces.
DIF: Application
REF: p. 283
OBJ: 10
57. What establishes the capillary colloidal osmotic pressure?
a. presence of electrolytes in plasma
b. presence of plasma proteins in blood
c. presence of RBCs in whole blood
d. presence of WBCs in whole blood
ANS: B
Proteins such as albumin are too large to pass through the pores of the capillary. Instead, these
proteins remain in the intravascular compartment and exert osmotic pressure, which draws
water and small solute molecules back into the capillaries. This plasma colloid osmotic
pressure is also sometimes called oncotic pressure.
Because these large proteins are negatively charged, they attract (but do not bind) an
equivalent amount of cations to the intravascular compartment. These cations have the effect
of increasing osmotic pressure within the capillary (Donnan effect).
DIF: Application
REF: p. 283
OBJ: 10
58. What does the Donnan effect describe?
a. how Cl exchanges for HCO3 in RBCs at the tissue level
b. how proteins attract cations, which increase capillary osmotic pressure.
c. relationship between colloidal osmotic pressure and fluid movement at tissue
d. relationship between osmotic and hydrostatic pressure at the capillary
ANS: B
DIF: Application
REF: p. 283
OBJ: 10
59. Describe the normal pressures or flows at the arterial end of the capillary.
a. Electrolytes move from the interstitium into the capillary.
b. Hydrostatic pressure is approximately 24 mm Hg.
c. Osmotic pressure is approximately 30 mm Hg.
d. Plasma minus the proteins flows into the interstitium.
ANS: D
For example, in a typical capillary, blood pressure is approximately 30 mm Hg at the arterial
end and approximately 20 mm Hg at the venous end (Figure 12-6). Colloid osmotic pressure
of the intravascular fluid remains constant at approximately 25 mm Hg. Hydrostatic pressure
along the capillary continually decreases. At the arterial end, hydrostatic pressure normally
exceeds osmotic pressure and water flows out of the vascular space into the interstitial space.
DIF: Application
REF: p. 283
OBJ: 10
60. Under normal circumstances, a small amount of fluid is filtered from the capillary in excess of
that which is absorbed. What prevents edema from occurring under these conditions?
a. The lymphatic system absorbs it and returns it to the circulatory system.
b. Tissue cells absorb this fluid and use it in the metabolic process.
c. Wandering macrophages use this excess fluid in hydrolyzing invaders.
d. Waste products dilute this, maintaining eutonic conditions.
ANS: A
This slight outward excess is balanced by fluid return through the lymphatic circulation.
DIF: Application
REF: p. 283
OBJ: 10
61. According to the Starling equilibrium equation, which of the following will NOT facilitate
fluid filtration from the capillaries into the interstitial space?
a. high capillary hydrostatic pressure
b. high capillary permeability
c. low capillary osmotic pressure
d. low interstitial osmotic pressure
ANS: D
These relationships may be expressed by the Starling equilibrium equation:
DIF: Analysis
REF: p. 283
OBJ: 10
62. Which of the following factors contributes to reabsorption of tissue fluid in dependent regions
of the body?
a. hydrostatic pressure of 100 mm Hg.
b. low capillary permeability
c. low interstitial osmotic pressure
d. pumping action of skeletal muscles
ANS: D
Because of hydrostatic effects, capillary pressure in the feet can be as high as 100 mm Hg
when an individual is standing. Reabsorption of tissue fluid can be accomplished although
hydrostatic pressure greatly exceeds colloidal osmotic pressure. Three factors favor
reabsorption under these circumstances. First, high intravascular hydrostatic pressure is
somewhat balanced by a proportionally greater interstitial pressure. Second, the “pumping”
action of the skeletal muscles surrounding leg veins lowers venous pressures. Third, lymph
flow back to the thorax is enhanced by a similar mechanism. This facilitates clearance of
excess interstitial fluid.
DIF: Application
REF: p. 283
OBJ: 10
63. The alveolar interstitial region of the lungs remains relatively “dry” primarily because of
what?
a. low capillary hydrostatic pressure
b. low capillary osmotic pressure
c. low capillary permeability
d. low interstitial osmotic pressure
ANS: A
To minimize interstitial fluid in the alveolarcapillary region, the hydrostatic pressure
difference must be kept low. The pulmonary circulation is in fact a low-pressure system. The
mean pulmonary vascular pressures are approximately one sixth of those in the systemic
circulation. Colloid osmotic pressure exceeds hydrostatic forces across the entire length of the
pulmonary capillaries in healthy individuals.
DIF: Application
REF: p. 283
OBJ: 10
64. What is a common cause for pulmonary edema due to increased hydrostatic pressure?
a. alveolarcapillary damage
b. chronic liver disease
c. failing left ventricle
d. failing right ventricle
ANS: C
In the lungs, edema caused by increased hydrostatic pressure often is a result of back pressure
from a failing left ventricle.
DIF: Application
REF: p. 284
OBJ: 10
65. What is a normal range for serum sodium?
a. 3.5 to 4.8 mEq/L
b. 67.0 to 75.0 mEq/L
c. 98.0 to 105.0 mEq/L
d. 136.0 to 145.0 mEq/L
ANS: D
The normal serum concentration of sodium ranges from 136 to 145 mEq/L.
DIF: Recall
REF: p. 285
OBJ: 11
66. Na+ reabsorption in the kidneys is governed mainly by the level of what hormone?
a. ADH
b. aldosterone
c. angiotensin
d. insulin
ANS: B
Sodium reabsorption in the kidneys is governed mainly by the level of aldosterone, which is
secreted by the adrenal cortex.
DIF: Application
REF: p. 285
OBJ: 11
67. Which of the following would NOT cause an abnormal loss of Na+ (hyponatremia)?
a. ascites
b. excessive sweating or fever
c. use of certain diuretics
d. steroid therapy
ANS: D
Abnormal losses of sodium can lead to hyponatremia and may occur for a number of reasons,
as shown in Table 12-5.
DIF: Application
REF: p. 285
OBJ: 11
68. What is the most prominent anion in the body?
a. Cl
b. HCO3
c. phosphate
d. sulfate
ANS: A
Chloride is the most prominent anion in the body.
DIF: Recall
REF: p. 286
OBJ: 11
69. What is a normal range for serum Cl?
a. 3.5 to 4.8 mEq/L
b. 98.0 to 106.0 mEq/L
c. 137.0 to147.0 mEq/L
d. 150.0 to 220.0 mEq/L
ANS: B
Normal serum levels of chloride (Cl) range between 98 and 106 mEq/L.
DIF: Recall
REF: p. 286
OBJ: 11
70. Which of the following correctly describes a facet of chloride?
a. A loss of Cl is equivalent to a gain in acid.
b. Cl is usually excreted with H+ as HCl.
c. Cl levels vary inversely with HCO3 levels.
d. Cl plays a key role in acid-base buffering.
ANS: C
The concentration of extracellular chloride is inversely proportional to that of the other major
anion, bicarbonate (HCO3).
DIF: Recall
REF: p. 286
71. What can cause hypochloremia?
1. diuretics
2. gastrointestinal loss
3. metabolic acidosis
a. 1 and 2
OBJ: 11
b. 1 and 3
c. 2 and 3
d. 1, 2, and 3
ANS: A
Abnormal chloride levels may occur for a variety of reasons (see Table 12-5).
DIF: Recall
REF: p. 285
OBJ: 11
72. Which of the following describe roles played by HCO3-?
1. HCO3 levels vary directly with Cl- levels.
2. It is the primary vehicle for blood carbon dioxide transport.
3. It plays a key role in acid-base homeostasis.
a. 1, 2, and 3
b. 1 and 3
c. 2 only
d. 2 and 3
ANS: D
HCO3 plays an important role in acid-base homeostasis and is the strong base in the
bicarbonate-carbonic acid buffer pair. HCO3 is the primary means for transporting carbon
dioxide from the tissues to the lungs. The ratio of HCO3 to carbonic acid in healthy
individuals is maintained near 20:1.
DIF: Application
REF: p. 286
OBJ: 11
73. What is the role of kidneys when a patient experiences acute respiratory alkalosis?
a. Cl shift enhances the body’s compensatory mechanisms.
b. HCO3 is eliminated in the urine.
c. It dumps Cl so as to retain HCO3.
d. The Hamburger phenomenon occurs.
ANS: B
In respiratory acidosis, the kidneys retain or produce HCO3 to buffer the additional acid
caused by CO2 retention. In respiratory alkalosis, the opposite occurs. A reciprocal
relationship exists between Cl and HCO3 concentrations. Bicarbonate retention is associated
with chloride excretion.
DIF: Application
REF: p. 286
OBJ: 11
74. What cation is the most prominent in the intracellular compartment?
a. Ca2+
b. K+
c. Li+
d. Na+
ANS: B
Potassium is the main cation of the intracellular compartment.
DIF: Recall
REF: p. 286
OBJ: 1
75. What is a normal K+ blood level?
a. 3.5 to 5.0 mEq/L.
b. 7.8 to 10.2 mEq/L
c. 22 to 26 mEq/L
d. 35 to 42 mEq/L
ANS: A
Serum K+ concentration normally ranges between only 3.5 and 5.0 mEq/L.
DIF: Recall
REF: p. 286
OBJ: 1
76. Which patients are prone to K+ depletion and hypokalemia?
1. postsurgical patients
2. those with renal disease
3. trauma victims
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 1, 2, and 3
ANS: D
Patients who have undergone surgery, have sustained trauma, or have renal disease often have
greater K losses.
DIF: Application
REF: p. 287
OBJ: 11
77. Which answer best describes the relationship between K+ movement and acid-base balance?
a. Excess extracellular H+ ions are exchanged for intracellular K+.
b. Extracellular acidosis results in serum hypokalemia.
c. Low-K+ diets are required following nasogastric suctioning.
d. When the extracellular pH rises, K+ moves out of the cells.
ANS: A
Serum K+ concentration is determined primarily by the pH of extracellular fluid and the size
of the intracellular K+ pool. In extracellular acidosis, excess H+ ions are exchanged for
intracellular K+. Movement of K+ from intracellular to extracellular spaces may produce
dangerous levels of hyperkalemia.
DIF: Application
REF: p. 287
OBJ: 11
78. What affect do metabolic acidosis and aldosterone have in common?
a. They both result in renal loss of K+.
b. There is a loss of HCO3 and Cl in the renal tubules.
c. There is retention of CO2 and Cl.
d. They both cause renal retention of HCO3.
ANS: A
Renal excretion of K+ is controlled by aldosterone levels. Aldosterone inhibits the enzyme
responsible for K+ transport in the distal renal tubular cells of the kidney. Metabolic acidosis
also inhibits the transport system.
DIF: Application
REF: p. 287
OBJ: 11
79. Hypokalemia disturbs cellular function in ALL but one of the following systems. Which one
does it NOT affect?
a. gastrointestinal
b. hepatic
c. neuromuscular
d. renal
ANS: B
Hypokalemia (reduced serum potassium) disturbs cellular function in a number of organ
systems. These include the gastrointestinal, neuromuscular, renal, and cardiovascular systems.
DIF: Recall
REF: p. 285
OBJ: 11
80. What is the most common cause of hyperkalemia?
a. cardiac arrest
b. metabolic alkalosis
c. renal failure
d. respiratory acidosis
ANS: C
Hyperkalemia (elevated serum potassium) is most common in renal insufficiency.
DIF: Recall
REF: p. 285
OBJ: 11
81. Which of the following drugs can be used to temporarily lower K+ in severe hyperkalemia?
a. corticosteroids
b. insulin
c. K-sparing diuretics
d. nonsteroidal antiinflammatory drugs
ANS: B
Temporary measures for reducing serum K+ levels include administration of insulin, calcium
gluconate, sodium salts, or large volumes of hypertonic glucose.
DIF: Recall
REF: p. 287
OBJ: 11
82. What is the normal serum calcium concentration?
a. 4.5 to 5.3 mg/dl.
b. 8.7 to 10.4 mg/dl
c. 98.0 to 105.0 mg/dl
d. 137 to 147 mg/dl
ANS: B
The normal serum calcium is 8.7 to 10.4 mg/dl, or about 4.5 to 5.25 mEq/L.
DIF: Recall
REF: p. 287
OBJ: 11
83. Which of the following describes serum Ca2+?
a. About 30% of the serum Ca2+ is ionized and combined with plasma anions.
b. Acidemia decreases the serum levels of ionized Ca2+.
c. More than half of the serum Ca2+ is nonionized and bound to plasma albumin.
d. Serum Ca2+ is present in three forms: ionized, protein bound, and complex.
ANS: D
Calcium is present in the blood in the following three forms: ionized, protein bound, and
complex. Approximately 50% of serum calcium is ionized (Ca2+) and is physiologically
active. An additional 10% forms calcium anion complexes. The remaining 40% is bound to
plasma proteins, primarily albumen. Ionized calcium is physiologically active in processes
such as enzyme activity, blood clotting, neuromuscular irritability, and bone calcification.
Acidemia increases, and alkalemia decreases, the concentration of Ca2+ in the serum.
DIF: Application
REF: p. 287
OBJ: 11
84. Clinical symptoms of hyponatremia would NOT include which of the following?
a. headache
b. bradycardia
c. lassitude
d. weakness
ANS: B
Symptoms of hyponatremia include: weakness, lassitude, apathy, headache, orthostatic
hypotension, and tachycardia.
DIF: Application
REF: p. 287
OBJ: 11
85. Clinical signs of hypokalemia would NOT include which of the following?
a. convulsions
b. electrocardiogram abnormalities
c. muscle weakness
d. paralysis
ANS: A
Symptoms of hypokalemia include: muscle weakness, paralysis, ECG abnormalities,
supraventricular arrhythmias, circulatory failure, and cardiac arrest.
DIF: Application
REF: p. 285
OBJ: 11
86. Signs and symptoms of hyperkalemia would NOT include which of the following?
a. cardiac arrest
b. electrocardiogram abnormalities
c. metabolic alkalosis
d. ventricular arrhythmias
ANS: C
Symptoms of hyperkalemia include: ECG changes, ventricular arrhythmias, and cardiac
arrest.
DIF: Application
REF: p. 285
OBJ: 11
87. Clinical manifestations of hypocalcemia would NOT include which of the following?
a. abdominal cramps
b. depressed tendon reflexes
c. electrocardiogram abnormalities
d. muscular twitching and spasm
ANS: B
Symptoms of hypocalcemia include: hyperactive tendon reflexes, muscle twitching, spasm,
abdominal cramps, ECG changes, and convulsions.
DIF: Application
REF: p. 285
OBJ: 11
88. Symptoms of hypercalcemia would include which of the following?
a. depression
b. diarrhea
c. hyperactive tendon reflexes
d. muscle fasciculation
ANS: A
Symptoms of hypercalcemia include: fatigue, depression, muscle weakness, anorexia, nausea,
vomiting, and constipation.
DIF: Application
REF: p. 285
OBJ: 11
89. What is hypercalcemia most often associated with?
a. hyperparathyroidism
b. kidney failure
c. pancreatitis
d. trauma
ANS: A
Hypercalcemia (increased levels of calcium) can result from numerous disorders. The most
common causes are hyperparathyroidism (increased intestinal calcium absorption) and in
malignancies (e.g., multiple myeloma, lung cancer).
Normal values for serum Mg2+ range from 1.7 to 2.1 mg/dl (1.3 to 2.1 mEq/L) in healthy
adults.
DIF: Recall
REF: p. 285
OBJ: 11
90. What are normal values for serum Mg2+?
a. 1.3 to 2.1 mEq/L.
b. 3.5 to 4.8 mEq/L
c. 9.0 to 10.5 mEq/L
d. 98.0 to 105.0 mEq/L
ANS: A
DIF: Recall
REF: p. 287
91. Where is most of the Mg2+ found in the body?
a. bound to phosphate
b. bound to proteins
c. in the cells
d. ionized
ANS: C
OBJ: 11
Most (99%) of the magnesium in the body is intracellular. Of the small portion in extracellular
spaces, 80% is ionized or bound to other ions (e.g. phosphate) with the remaining 20% bound
to proteins.
DIF: Recall
REF: p. 287
OBJ: 11
92. What is the normal range for serum phosphate?
a. 1.2 to 2.3 mEq/L.
b. 3.5 to 5.8 mEq/L
c. 9.0 to 10.5 mEq/L
d. 98.0 to 106.0 mEq/L
ANS: A
Only about 1% of the total body phosphorus is available as free serum compounds, so the
serum level (1.2 to 2.3 mEq/L) does not necessarily reflect total body content.
DIF: Recall
REF: p. 288
OBJ: 11
93. Which of the following is FALSE about phosphate?
a. Organic phosphate is the primary extracellular cation.
b. Inorganic phosphate plays a primary role in energy metabolism.
c. Phosphate is the main urinary buffer for titratable acid excretion.
d. Serum phosphate levels range from 1.2 to 2.3 mEq/L.
ANS: A
Organic phosphate (HPO42–) is the main anion within cells. Inorganic phosphate plays a
primary role in the metabolism of cellular energy, being the source from which adenosine
triphosphate is synthesized. In acid-base homeostasis, phosphate is the main urinary buffer for
titratable acid excretion.
DIF: Application
REF: p. 288
OBJ: 11
94. The ease with which a solute dissolves into a solvent is at least partially determined by which
of the following?
a. pressure of a solid
b. solute concentration
c. level of 2,3-DPG
d. solvent conductivity
ANS: B
The ease with which a solute dissolves in a solvent is its solubility, which is influenced by
five factors:
1. Nature of the solute. The ease with which substances go into a solution in a given solvent
depends on the forces of the solute-solute molecules and varies widely.
2. Nature of the solvent. A solvent’s ability to dissolve a solute depends on the bonds of the
solvent-solvent molecules, and also varies widely.
3. Temperature. Solubility of most solids increases with increased temperature. However, the
solubility of gases varies inversely with temperature.
4. Pressure. The solubility of solids and liquids is not greatly affected by pressure. The
solubility of gases in liquids, however, varies directly with pressure.
5. Concentration. The concentration of a solute or available solvent will have an effect of how
much of the substance goes into solution.
DIF: Application
REF: p. 273
OBJ: 2
95. Osmolality is defined as:
a. the ratio of solute to solvent
b. the ratio of solvent to solute
c. the ability of cell walls to be semipermeable
d. the attractive force of the solute within the solution
ANS: A
Osmolality is defined as the ratio of solute to solvent. In physiology the solvent is water.
Osmotic pressure depends on the number of particles in solution but not on their charge or
identity.
DIF: Application
REF: p. 275
OBJ: 3
96. Starling Forces, or fluid movement due to filtration across the wall of a capillary is dependent
upon:
1. hydrostatic & oncotic pressure gradients across the capillary
2. hydraulic (hydrostatic) in the vessel
3. colloid osmotic pressure (COP) in the vessel
4. colloid osmotic pressure (COP) in the tissue space
a. 1 and 4
b. 1, 2, and 4
c. 2 and 3
d. 1, 2, 3, and 4
ANS: D
Ernst Starling was a 19th century British physiologist who studied fluid transport across
membranes. His hypothesis states that the fluid movement due to filtration across the wall of a
capillary is dependent upon both the hydrostatic and oncotic pressure gradients across the
capillary. The driving force for fluid filtration across the wall of the capillary is determined by
four separate pressures: hydraulic (hyrdrostatic), and colloid osmotic pressure (COP) both
within the vessel and in the tissue space respectively.
DIF: Application
REF: p. 283
OBJ: 1
97. The most common causes of acute hyponatremia include:
1. postoperative iatrogenic causes
2. not drinking enough water
3. self-induced due to water intoxication
4. not eating enough foods containing sodium
a. 1 and 3
b. 2 and 3
c. 1, 2, and 4
d. 1, 2, 3 and 4
ANS: A
Hyponatremia can lead to cerebral edema due to a change in osmotic pressure. The two most
common causes for acute hyponatremia are postoperative iatrogenic and self-induced due to
water intoxication.
DIF: Application
REF: p. 285
OBJ: 11
98. Hyponatremia can lead to which of the following problems?
1. impaired cognitive function
2. negative effects on gait stability
3. renal insufficiency
4. cerebral edema
a. 1 and 3
b. 2 and 3
c. 1, 2, and 4
d. 1, 2, 3 and 4
ANS: C
Once considered to be benign, mild hyponatremia has been shown in recent studies to have a
significant impact on a patient`s cognitive function as well as his or her gait stability, it is
thought to be a contributing factor in falls. Hyponatremia can lead to cerebral edema due to a
change in osmotic pressure.
DIF: Application
REF: p. 285
OBJ: 11