NUR 2392 MDC 2 EXAM 2-WITH 100%
ACCURATE SOLUTIONS-2025
Chapter 14- Concepts of Acid-Base Balance
1. Which pH value indicates the highest concentration of free hydrogen ions in the blood and other
extracellular fluids? A. 7.57
B. 7.47
C. 7.37
D. 7.27
The blood level of free hydrogen ions is calculated in negative logarithm units. This calculation
makes the value of pH inversely related (negatively related) to the concentration of free hydrogen
ions. Thus, the lower the pH value of a fluid, the higher the level of free hydrogen ions in that fluid.
2. Which client arterial blood gas results would the nurse interpret as within normal limits? A. pH
7.28, PaCO2 24, bicarbonate 15, PaO2 95
B. pH 7.45, PaCO2 41, bicarbonate 25, PaO2 97
C. pH 7.35, PaCO2 24, bicarbonate 15, PaO2 95
D. pH 7.30, PaCO2 66, bicarbonate 38, PaO2 70 The normal arterial pH range is 7.35-7.45. The
normal PaCO2 range is 35-45 mm Hg.
The normal PaO2 range is 80-100 mm Hg.
The normal arterial bicarbonate range is 21-28 mEq/L (mmol/L).
3. Which arterial blood pH level can be fatal? A. 7.22 B. 7.11
C. 7.05
D. 6.85
,An arterial pH below 6.85 is considered incompatible with life because all vital organ functions would
be inhibited.
4. By which mechanism do buffers help maintain arterial blood pH within the normal range? A.
Binding excess free hydrogen ions
B. Increasing kidney excretion of free hydrogen ions
C. Triggering increased bicarbonate production in the pancreas
D. Stimulating respiratory neurons to increase the rate and depth of ventilation
Buffers in body fluids act like hydrogen ion “sponges,” soaking up hydrogen ions when too many are
present and squeezing out hydrogen ions when very few are present. Buffers have no mechanism to
change kidney, pancreas, or neuronal function.
5. What changes in body functions does the nurse anticipate in a client who has lower than normal
blood pH levels? Select all that apply.
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A. Decreased serum potassium levels
B. Increased effectiveness of drugs
C. Reduced function of hormones
D. Increased function of enzymes
E. Decreased electrical conduction in the heart
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B. The concentrations of hydrogen ions and carbon dioxide are directly related, with an increase or
F. Decreased skeletal muscle strength
Higher concentration of hydrogen ions (reflected by a lower pH) increases (not decreases) serum
potassium levels, decreases effectiveness of drugs, reduces function of hormones, reduces function
,of enzymes, slows electrical conduction through the heart (because of the elevated potassium
levels) and decreases muscle strength.
6. The continuous normal function of which organs is most critical for acid-base balance? Select all
that apply. A. Adrenal glands
B. Bladder
C. Heart
D. Kidneys
E. Liver
F. Lungs
The kidneys are critical in retaining and eliminating hydrogen ions and bicarbonate to maintain acid-
base balance. The lungs are the organs that control carbon dioxide elimination. Normal functioning
of both these organs are necessary for acid-base balance. A problem interfering with the function of
either of them can lead to life-threatening acid-base imbalances. The heart, liver, and bladder have
no role in acid-base balance. Although specific adrenal gland problems are indirectly associated with
acid-base imbalances, they do not directly affect acid-base balance.
7. Which statement most accurately describes the relationship between the hydrogen ion
concentration and carbon dioxide concentration in extracellular fluids? A. Because carbon dioxide is
a gas and hydrogen ions are electrolytes, these two substances have no relationship in extracellular
fluids.
decrease in one always resulting in a corresponding increase or decrease in the other.
C. Carbon dioxide buffers hydrogen ions, thus these two concentrations are inversely related to each
other. The greater the carbon dioxide concentration, the fewer hydrogen ions present in that fluid.
D. Hydrogen ions and carbon dioxide ions exist in a balanced relationship as a result of their charges.
The positively charged hydrogen ions are attracted to the negatively charged carbon dioxide ions,
forming an electrically neutral substance.
Through the action of the carbonic anhydrase reaction, the concentration of hydrogen ions is
directly related to the concentration of carbon dioxide in the blood. Any condition that increases the
concentration of one also increases the concentration of the other. Carbon dioxide is not a buffer.
8. Which statement about compensation for acid-base imbalance is accurate? A. The respiratory
system is less sensitive to acid-base changes.
B. The respiratory system can begin compensation within seconds to minutes.
C. The renal system is less powerful than the respiratory system.
, D. The renal system is more sensitive to acid-base changes.
The healthy respiratory system can compensate for acid-base imbalances from other causes. It
represents the second line of defense to prevent an imbalance and can begin to compensate within
seconds to minutes after a change in hydrogen ion concentration (reflected as a corresponding
change in carbon dioxide). The central chemoreceptors controlling rate and depth of ventilation are
extremely sensitive to changes in carbon dioxide levels.
9. Which condition or response is an example of physiologic compensation to maintain acid-base
balance? A. Increasing rate and depth of respiration when running 2000 feet
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A. Renal mechanisms are stronger in regulating acid-base balance but slower to respond than
respiratory
B. Increasing urine output when blood pressure increases during heavy exercise
C. Drinking more fluids when spending an extended period of time in a dry environment
D. Shifting body weight when pain occurs as a result of remaining in one position for too long
The respiratory system increases its activity by “blowing off” excess carbon dioxide that developed
as a result of lactic acidosis occurring in skeletal muscle when blood flow and oxygenation were
insufficient to meet the increased demand for oxygen (oxygen debt) created during increased
skeletal muscle metabolism.
mechanisms.
10. Which statements correctly apply to acid-base balance in the body? Select all that apply.
B. The immediate binding of excess hydrogen ions occurs primarily in the red blood cells.
C. Combined acidosis is less severe than either metabolic acidosis or respiratory acidosis alone.
D. Respiratory acidosis is caused by a patent airway.
E. Acid-base balance occurs through control of hydrogen ion production and elimination.
F. Buffers are the third-line defense against acid-base imbalances in the body.
Acid-base balance is maintained by controlling the body’s hydrogen ion production with mechanisms
to eliminate hydrogen ions at the same rate they are produced. Renal mechanisms for control of
acid-base balance are the most powerful but are slow to start, usually requiring that an acid-base
disturbance be present for at least 24 hours before becoming active. The first line of defense against
acid-base changes are the buffers in the blood, other extracellular fluids, and inside cells. Red blood
ACCURATE SOLUTIONS-2025
Chapter 14- Concepts of Acid-Base Balance
1. Which pH value indicates the highest concentration of free hydrogen ions in the blood and other
extracellular fluids? A. 7.57
B. 7.47
C. 7.37
D. 7.27
The blood level of free hydrogen ions is calculated in negative logarithm units. This calculation
makes the value of pH inversely related (negatively related) to the concentration of free hydrogen
ions. Thus, the lower the pH value of a fluid, the higher the level of free hydrogen ions in that fluid.
2. Which client arterial blood gas results would the nurse interpret as within normal limits? A. pH
7.28, PaCO2 24, bicarbonate 15, PaO2 95
B. pH 7.45, PaCO2 41, bicarbonate 25, PaO2 97
C. pH 7.35, PaCO2 24, bicarbonate 15, PaO2 95
D. pH 7.30, PaCO2 66, bicarbonate 38, PaO2 70 The normal arterial pH range is 7.35-7.45. The
normal PaCO2 range is 35-45 mm Hg.
The normal PaO2 range is 80-100 mm Hg.
The normal arterial bicarbonate range is 21-28 mEq/L (mmol/L).
3. Which arterial blood pH level can be fatal? A. 7.22 B. 7.11
C. 7.05
D. 6.85
,An arterial pH below 6.85 is considered incompatible with life because all vital organ functions would
be inhibited.
4. By which mechanism do buffers help maintain arterial blood pH within the normal range? A.
Binding excess free hydrogen ions
B. Increasing kidney excretion of free hydrogen ions
C. Triggering increased bicarbonate production in the pancreas
D. Stimulating respiratory neurons to increase the rate and depth of ventilation
Buffers in body fluids act like hydrogen ion “sponges,” soaking up hydrogen ions when too many are
present and squeezing out hydrogen ions when very few are present. Buffers have no mechanism to
change kidney, pancreas, or neuronal function.
5. What changes in body functions does the nurse anticipate in a client who has lower than normal
blood pH levels? Select all that apply.
2
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A. Decreased serum potassium levels
B. Increased effectiveness of drugs
C. Reduced function of hormones
D. Increased function of enzymes
E. Decreased electrical conduction in the heart
3
Downloaded by Anna Maina ()
B. The concentrations of hydrogen ions and carbon dioxide are directly related, with an increase or
F. Decreased skeletal muscle strength
Higher concentration of hydrogen ions (reflected by a lower pH) increases (not decreases) serum
potassium levels, decreases effectiveness of drugs, reduces function of hormones, reduces function
,of enzymes, slows electrical conduction through the heart (because of the elevated potassium
levels) and decreases muscle strength.
6. The continuous normal function of which organs is most critical for acid-base balance? Select all
that apply. A. Adrenal glands
B. Bladder
C. Heart
D. Kidneys
E. Liver
F. Lungs
The kidneys are critical in retaining and eliminating hydrogen ions and bicarbonate to maintain acid-
base balance. The lungs are the organs that control carbon dioxide elimination. Normal functioning
of both these organs are necessary for acid-base balance. A problem interfering with the function of
either of them can lead to life-threatening acid-base imbalances. The heart, liver, and bladder have
no role in acid-base balance. Although specific adrenal gland problems are indirectly associated with
acid-base imbalances, they do not directly affect acid-base balance.
7. Which statement most accurately describes the relationship between the hydrogen ion
concentration and carbon dioxide concentration in extracellular fluids? A. Because carbon dioxide is
a gas and hydrogen ions are electrolytes, these two substances have no relationship in extracellular
fluids.
decrease in one always resulting in a corresponding increase or decrease in the other.
C. Carbon dioxide buffers hydrogen ions, thus these two concentrations are inversely related to each
other. The greater the carbon dioxide concentration, the fewer hydrogen ions present in that fluid.
D. Hydrogen ions and carbon dioxide ions exist in a balanced relationship as a result of their charges.
The positively charged hydrogen ions are attracted to the negatively charged carbon dioxide ions,
forming an electrically neutral substance.
Through the action of the carbonic anhydrase reaction, the concentration of hydrogen ions is
directly related to the concentration of carbon dioxide in the blood. Any condition that increases the
concentration of one also increases the concentration of the other. Carbon dioxide is not a buffer.
8. Which statement about compensation for acid-base imbalance is accurate? A. The respiratory
system is less sensitive to acid-base changes.
B. The respiratory system can begin compensation within seconds to minutes.
C. The renal system is less powerful than the respiratory system.
, D. The renal system is more sensitive to acid-base changes.
The healthy respiratory system can compensate for acid-base imbalances from other causes. It
represents the second line of defense to prevent an imbalance and can begin to compensate within
seconds to minutes after a change in hydrogen ion concentration (reflected as a corresponding
change in carbon dioxide). The central chemoreceptors controlling rate and depth of ventilation are
extremely sensitive to changes in carbon dioxide levels.
9. Which condition or response is an example of physiologic compensation to maintain acid-base
balance? A. Increasing rate and depth of respiration when running 2000 feet
4
Downloaded by Anna Maina ()
A. Renal mechanisms are stronger in regulating acid-base balance but slower to respond than
respiratory
B. Increasing urine output when blood pressure increases during heavy exercise
C. Drinking more fluids when spending an extended period of time in a dry environment
D. Shifting body weight when pain occurs as a result of remaining in one position for too long
The respiratory system increases its activity by “blowing off” excess carbon dioxide that developed
as a result of lactic acidosis occurring in skeletal muscle when blood flow and oxygenation were
insufficient to meet the increased demand for oxygen (oxygen debt) created during increased
skeletal muscle metabolism.
mechanisms.
10. Which statements correctly apply to acid-base balance in the body? Select all that apply.
B. The immediate binding of excess hydrogen ions occurs primarily in the red blood cells.
C. Combined acidosis is less severe than either metabolic acidosis or respiratory acidosis alone.
D. Respiratory acidosis is caused by a patent airway.
E. Acid-base balance occurs through control of hydrogen ion production and elimination.
F. Buffers are the third-line defense against acid-base imbalances in the body.
Acid-base balance is maintained by controlling the body’s hydrogen ion production with mechanisms
to eliminate hydrogen ions at the same rate they are produced. Renal mechanisms for control of
acid-base balance are the most powerful but are slow to start, usually requiring that an acid-base
disturbance be present for at least 24 hours before becoming active. The first line of defense against
acid-base changes are the buffers in the blood, other extracellular fluids, and inside cells. Red blood
