Chapter 22: Acid-Base Balance

Patton: The Human Body in Health & Disease, 7th Edition

Multiple Choice

1. The function of H+ ions in the body is a. maintenance of the cell membrane. b. conduction of nerve impulses. c. function of cellular enzymes. d. stimulation of muscle contraction.

ANS: C PTS: 1 DIF: Memorization

REF: p. 601 TOP: Introduction

2. A solution with a pH of 3 a. is an acid solution. b. is an alkaline solution. c. has more OH ions than H+ ions. d. both B and C.

ANS: A PTS: 1 DIF: Application REF: p. 602 TOP: pH of body fluids

3. A solution with a pH of 9 a. is an acid solution. b. is an alkaline solution. c. has more OH ions than H+ ions. d. both B and C.

ANS: D PTS: 1 DIF: Application REF: p. 602 TOP: pH of body fluids a. Arterial blood b. Stomach acid c. Venous blood d. Saliva

4. Which of the following body fluids has the lowest pH?

ANS: B PTS: 1 DIF: Memorization

REF: p. 602 TOP: pH of body fluids a. Arterial blood b. Venous blood c. Stomach acid d. Both A and B have the same pH, which is higher than stomach acid.

5. Which of the following body fluids has the highest pH?

ANS: A PTS: 1 DIF: Memorization

REF: p. 602 TOP: pH of body fluids

6. A solution with a pH of 4 a. has 100 times more H+ ions than a solution with a pH of 2. b. has 100 times fewer H+ ions than a solution with a pH of 2. c. is considered an alkaline solution. d. both B and C.

ANS: B PTS: 1 DIF: Application REF: p. 602

TOP: pH of body fluids

7. A solution with a pH of 8 a. is more alkaline than arterial blood. b. is more acidic than arterial blood. c. contains more H+ ions than arterial blood. d. both B and C.

ANS: A PTS: 1 DIF: Application REF: p. 602

TOP: pH of body fluids a. Buffers in the blood b. The stomach absorbing acid c. The lungs removing carbon dioxide d. The kidneys removing H+ and OH ions

8. Which of the following is not considered a mechanism for regulating the pH of body fluids?

ANS: B PTS: 1 DIF: Memorization

REF: p. 602 TOP: Mechanisms that control pH of body fluids

9. The slightly lower pH of venous blood compared with arterial blood comes primarily from a. absorbing hydrochloric acid from the digestive system. b. the lactic acid from muscle metabolism. c. the higher concentration of carbonic acid from cell metabolism. d. all of the above.

ANS: C PTS: 1 DIF: Application REF: p. 602

TOP: Mechanisms that control pH of body fluids a. The buffers in the blood b. The kidneys c. The lungs d. Both B and C

10. Which of the following is considered a physiological pH control mechanism?

ANS: D PTS: 1 DIF: Memorization

REF: p. 603 TOP: Mechanisms that control pH of body fluids a. The buffers in the blood b. The kidneys c. The lungs d. Both B and C

11. Which of the following is considered a chemical pH control mechanism?

ANS: A PTS: 1 DIF: Memorization

REF: p. 603 TOP: Mechanisms that control pH of body fluids

12. The buffering of HCl by the H2CO3–NaHCO3 buffer pair would a. convert the strong HCl into the weaker H2CO3. b. cause a smaller increase of H+ ions in the blood. c. decrease the amount of NaHCO3 in the blood. d. all of the above.

ANS: D PTS: 1 DIF: Memorization

REF: p. 604 TOP: Mechanisms that control pH of body fluids

13. The buffering of NaOH by the H2CO3–NaHCO3 buffer pair would a. convert a strong base into a weak acid. b. decrease the amount of H2CO3 in the blood. c. cause the pH to rise to its normal value. d. cause all of the above.

ANS: B PTS: 1 DIF: Application REF: p. 605

TOP: Mechanisms that control pH of body fluids a. lower pH b. lower concentration of carbon dioxide c. higher concentration of H+ ions d. both A and C

14. Blood leaving the lungs has a _____ than blood entering the lungs.

ANS: B PTS: 1 DIF: Application REF: p. 602

TOP: Mechanisms that control pH of body fluids

15. One unique aspect of kidney regulation of pH is that it a. is the only site of carbonic anhydrase that can quickly convert carbon dioxide and water to carbonic acid. b. can excrete excess acid. c. can excrete excess base. d. both A and B.

ANS: C PTS: 1 DIF: Application REF: pp. 606-607

TOP: Mechanisms that control pH of body fluids

16. In blood acidosis, the a. number of H+ ions in the blood increases. b. pH of the blood falls below 6.5. c. number of OH ions in the blood increases. d. both A and B.

ANS: A PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances

17. Blood alkalosis a. causes the pH of the blood to drop. b. occurs more often than blood acidosis. c. is caused by an increase in base or a loss of acid. d. both B and C.

ANS: C PTS: 1 DIF: Application REF: p. 607

TOP: pH imbalances a. Respiratory acidosis b. Metabolic acidosis c. Respiratory alkalosis d. Metabolic alkalosis

18. Which of the following is caused by bicarbonate deficit?

ANS: B PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances a. Respiratory acidosis b. Metabolic acidosis c. Respiratory alkalosis d. Metabolic alkalosis

19. Which of the following is caused by H2CO3 deficit?

ANS: C PTS: 1 DIF: Memorization

REF: p. 609 TOP: pH imbalances a. Respiratory acidosis b. Metabolic acidosis c. Respiratory alkalosis d. Metabolic alkalosis

20. Which of the following is caused by H2CO3 excess?

ANS: A PTS: 1 DIF: Memorization

REF: p. 608 TOP: pH imbalances

21. A water solution with a pH of 7 a. is an acid. b. has equal numbers of OH and H+ ions. c. is a base. d. contains neither OH nor H+ .

ANS: B PTS: 1 DIF: Memorization

REF: p. 601 TOP: pH of body fluids a. Arterial blood and venous blood are slightly alkaline. b. Arterial blood and venous blood are slightly acidic. c. Arterial blood is slightly acidic, and venous blood is slightly basic. d. Venous blood is slightly acidic, and arterial blood is slightly basic.

22. Which of the following statements is true?

ANS: A PTS: 1 DIF: Memorization

REF: p. 602 TOP: pH of body fluids

23. Carbonic anhydrase is a(n) a. buffer that works in the blood. b. enzyme. c. buffer that works in the lungs. d. buffer that works in the kidneys.

ANS: B PTS: 1 DIF: Memorization

REF: p. 602 TOP: Mechanisms that control pH of body fluids a. 50 b. 60 c. 40 d. 30

24. The lungs are able to remove the equivalent of _____ L of carbonic acid a day.

ANS: D PTS: 1 DIF: Memorization

REF: p. 603 TOP: Mechanisms that control pH of body fluids a. The lungs can remove larger amounts of acid from the body than the kidneys. b. The kidneys can remove larger amounts of acid from the body than the lungs. c. Unlike the lungs, the kidneys can remove base from the body. d. Both B and C are true.

25. Which of the following statements is true?

ANS: D PTS: 1 DIF: Memorization

REF: p. 606 TOP: Urinary mechanism of pH control

Matching

Match each term with its corresponding description or definition.

a. Buffer b. Metabolic acidosis c. Acid solution d. Respiratory alkalosis e. Respiratory system f. Metabolic alkalosis g. Alkaline solution h. Kidney system i. Respiratory acidosis j. Neutral solution

1. Solution that has a pH of 7 with an equal number of H+ and OH ions

2. The only pH-regulating system that can excrete base

3. A substance that prevents a sharp change in the pH of a solution when a strong acid or base is added to it

4. A solution with a pH greater than 7 and a higher concentration of OH ions than H+ ions

5. System that helps regulate the pH of the blood by removing carbon dioxide

6. Solution that has a pH less than 7 and a higher concentration of H+ ions than OH ions

7. Condition that is caused by a carbonic acid excess

8. Condition that is caused by a bicarbonate excess

9. Condition that is caused by a bicarbonate deficit

10. Condition that is caused by carbonic acid deficit

1. ANS: J PTS: 1 DIF: Memorization

REF: p. 601 TOP: pH of body fluids

2. ANS: H PTS: 1 DIF: Memorization

REF: p. 606 TOP: Mechanisms that control pH of body fluids

3. ANS: A PTS: 1 DIF: Memorization

REF: p. 603 TOP: Mechanisms that control pH of body fluids

4. ANS: G PTS: 1 DIF: Memorization

REF: p. 602 TOP: pH of body fluids

5. ANS: E PTS: 1 DIF: Memorization

REF: p. 606 TOP: Mechanisms that control pH of body fluids

6. ANS: C PTS: 1 DIF: Memorization

REF: p. 602 TOP: pH of body fluids

7. ANS: I PTS: 1 DIF: Memorization

REF: p. 608 TOP: pH imbalances

8. ANS: F PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances

9. ANS: B PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances

10. ANS: D PTS: 1 DIF: Memorization

REF: p. 609 TOP: pH imbalances

Short Answer

1. What is the definition of acid-base balance? What proteins are most affected if the acid-base balance is not maintained?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 601 TOP: Introduction

2. Explain the pH scale. Which body fluid has the highest pH? Which has the lowest?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: pp. 601-602 TOP: pH of body fluids

3. If one solution has a pH of 5 and a second solution has 10 times more H+ ions than the first solution, what would the pH level of the second solution be?

ANS: 4

PTS: 1 DIF: Application REF: p. 602 TOP: pH of body fluids

4. What two pH-regulating systems are referred to as physiological pH control mechanisms?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 603

TOP: Mechanisms that control pH of body fluids

5. What is the function of carbonic anhydrase?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: pp. 602-603

TOP: Mechanisms that control pH of body fluids

6. Explain how the buffer system functions to buffer a strong acid.

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 604

TOP: Mechanisms that control pH of body fluids

7. Explain how the buffer system functions to buffer a strong base.

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: pp. 603-604

TOP: Mechanisms that control pH of body fluids

8. What is a fixed acid? Give an example of a fixed acid and a nonfixed acid found in the body.

ANS: Answers will vary.

PTS: 1 DIF: Application REF: p. 605

TOP: Mechanisms that control pH of body fluids

9. List the four changes in the blood that result from the buffering of a fixed acid in the tissue capillaries.

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: pp. 605-606

TOP: Mechanisms that control pH of body fluids

10. Explain how the respiratory mechanism controls blood pH. What effect would a prolonged period of decreased respiration have on blood pH?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 606

TOP: Mechanisms that control pH of body fluids

11. Would you expect the blood in the pulmonary artery or in the pulmonary vein to have the higher pH? Explain your answer.

ANS: Answers will vary.

PTS: 1 DIF: Application REF: p. 602

TOP: Mechanisms that control pH of body fluids

12. Explain how the urinary mechanism controls blood pH.

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: pp. 606-607

TOP: Mechanisms that control pH of body fluids

13. Define blood acidosis and blood alkalosis.

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 607

TOP: pH imbalances

14. A condition called metabolic acidosis can be caused by a bicarbonate deficit. What can cause a bicarbonate deficit?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 607

TOP: pH imbalances

15. A condition called metabolic alkalosis can be caused by a bicarbonate excess. What can cause a bicarbonate excess?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 607 TOP: pH imbalances

16. A condition called respiratory acidosis can be caused by a carbonic acid excess. What can cause a carbonic acid excess?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 608

TOP: pH imbalances

17. A condition called respiratory alkalosis can be caused by a carbonic acid deficit. What can cause a carbonic acid deficit?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 609 TOP: pH imbalances

18. What is uncompensated metabolic acidosis? How does it become compensated metabolic acidosis?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: pp. 609-610 TOP: pH imbalances

19. In uncompensated metabolic acidosis, what mechanism removes the excess H2CO3?

ANS: Answers will vary.

PTS: 1 DIF: Memorization REF: p. 610 TOP: pH imbalances

20. Suppose the 20:1 ratio needed by the H2CO3–NaHCO3 buffer pair is disrupted and the concentration of NaHCO3 in the blood needs to be lowered. What mechanism could accomplish this?

ANS: Answers will vary.

PTS: 1 DIF: Application REF: pp. 603-606 TOP: pH imbalances | Mechanisms that control pH of body fluids

TRUE/FALSE

1. Maintaining acid-base balance means keeping the concentration of hydrogen ions in body fluids relatively constant.

ANS: T PTS: 1 DIF: Memorization

REF: p. 601 TOP: Introduction

2. Because the functioning of proteins such as enzymes and hemoglobin depends on a proper pH level, pH must be regulated closely.

ANS: T PTS: 1 DIF: Memorization

REF: p. 601 TOP: Introduction

3. The pH scale measures the concentration of OH ions in solution.

ANS: F PTS: 1 DIF: Memorization

REF: p. 601 TOP: pH of body fluids

4. A solution with a pH of 9 has more hydrogen ions than hydroxide ions.

ANS: F PTS: 1 DIF: Application REF: p. 602

TOP: pH of body fluids

5. A solution with a pH of 9 is considered an alkaline solution.

ANS: T PTS: 1 DIF: Memorization

REF: p. 602 TOP: pH of body fluids

6. A solution with a pH of 13 contains more hydroxide ions than a solution with a pH of 11.

ANS: T PTS: 1 DIF: Application REF: p. 602

TOP: pH of body fluids

7. A solution with a pH of 5 contains more hydrogen ions than a solution with a pH of 2.

ANS: F PTS: 1 DIF: Application REF: p. 602

TOP: pH of body fluids

8. A solution with a pH of 5 is considered an acid.

ANS: T PTS: 1 DIF: Memorization

REF: p. 602 TOP: pH of body fluids

9. A solution with a pH of 5 has 100 times more hydrogen ions than a solution with a pH of 3.

ANS: F PTS: 1 DIF: Application REF: p. 602

TOP: pH of body fluids

10. A solution with a pH of 2 has 1,000 times more hydrogen ions than a solution with a pH of 5.

ANS: T PTS: 1 DIF: Application REF: p. 602

TOP: pH of body fluids

11. Venous blood is the body fluid with the highest pH.

ANS: F PTS: 1 DIF: Application REF: p. 602

TOP: pH of body fluids

12. Stomach acid is the body fluid with the lowest pH.

ANS: T PTS: 1 DIF: Memorization

REF: p. 602 TOP: pH of body fluids

13. Pure water, with a pH of 7, is neither acid nor base because it contains neither hydrogen ions nor hydroxide ions.

ANS: F PTS: 1 DIF: Application REF: p. 601

TOP: pH of body fluids

14. The body has three mechanisms for regulating pH: the buffer mechanism, the respiratory mechanism, and the digestive mechanism.

ANS: F PTS: 1 DIF: Memorization

REF: p. 602 TOP: Mechanisms that control pH of body fluids

15. The function of carbonic anhydrase is to convert carbon dioxide and water to carbonic acid.

ANS: T PTS: 1 DIF: Memorization

REF: p. 602 TOP: Mechanisms that control pH of body fluids

16. The physiological pH control mechanisms react more quickly to stabilize pH than do the chemical pH control mechanisms.

ANS: F PTS: 1 DIF: Memorization

REF: p. 603 TOP: Mechanisms that control pH of body fluids

17. The lungs work more rapidly to stabilize pH than do the kidneys.

ANS: T PTS: 1 DIF: Memorization

REF: p. 606 TOP: Mechanisms that control pH of body fluids

18. The function of a buffer pair is to convert a strong acid into a weak acid.

ANS: T PTS: 1 DIF: Application REF: p. 604

TOP: Mechanisms that control pH of body fluids

19. When acid is added to a buffered solution, the pH will actually rise.

ANS: F PTS: 1 DIF: Memorization

REF: p. 604 TOP: Mechanisms that control pH of body fluids

20. If a base were added to the buffer pair H2CO3–NaHCO3, the concentration of NaHCO3 would drop.

ANS: F PTS: 1 DIF: Application REF: p. 604

TOP: Mechanisms that control pH of body fluids

21. If a base were added to the buffer pair H2CO3–NaHCO3, the concentration of H2CO3 would drop.

ANS: T PTS: 1 DIF: Application REF: p. 604

TOP: Mechanisms that control pH of body fluids

22. If an acid were added to the buffer pair H2CO3–NaHCO2, the concentration of NaHCO3 would drop.

ANS: T PTS: 1 DIF: Application REF: p. 604

TOP: Mechanisms that control pH of body fluids

23. The NaHCO3 buffer system buffers lactic acid.

ANS: T PTS: 1 DIF: Memorization

REF: p. 604 TOP: Mechanisms that control pH of body fluids

24. Lactic acid and carbonic acid are referred to as fixed acids.

ANS: F PTS: 1 DIF: Application REF: p. 604

TOP: Mechanisms that control pH of body fluids

25. Because carbonic acid can be broken down to carbon dioxide and water, it is not considered a fixed acid.

ANS: T PTS: 1 DIF: Application REF: p. 602

TOP: Mechanisms that control pH of body fluids

26. The contribution of the lungs to pH control is the removal of carbon dioxide from the blood.

ANS: T PTS: 1 DIF: Memorization

REF: p. 602 TOP: Mechanisms that control pH of body fluids

27. Blood in the pulmonary artery has a lower pH than the blood in the aorta.

ANS: T PTS: 1 DIF: Application REF: p. 602

TOP: Mechanisms that control pH of body fluids

28. Blood in the pulmonary vein has a lower pH than the blood in the superior vena cava.

ANS: F PTS: 1 DIF: Application REF: p. 602

TOP: Mechanisms that control pH of body fluids

29. The amount of carbonic acid is lower in the pulmonary vein than it is in the pulmonary artery.

ANS: T PTS: 1 DIF: Application REF: p. 602

TOP: Mechanisms that control pH of body fluids

30. Anything that decreases respiration will eventually cause alkalosis.

ANS: F PTS: 1 DIF: Memorization

REF: p. 606 TOP: Mechanisms that control pH of body fluids

31. One of the things that the kidneys can do that the lungs cannot do is to excrete base.

ANS: T PTS: 1 DIF: Memorization

REF: p. 606 TOP: Mechanisms that control pH of body fluids

32. When the kidneys work to raise the pH of the blood, the blood becomes more alkaline and the urine becomes more acidic.

ANS: T PTS: 1 DIF: Memorization

REF: p. 606 TOP: Mechanisms that control pH of body fluids

33. One of the ways the kidneys help raise the pH of the body is by excreting NaH2PO4 rather than Na2HPO4.

ANS: T PTS: 1 DIF: Application REF: pp. 606-607

TOP: Mechanisms that control pH of body fluids

34. When the kidneys have acidified the urine, the level of NaHCO3 in the blood leaving the kidneys is much lower than the level of NaHCO3 in the blood entering the kidneys.

ANS: F PTS: 1 DIF: Application REF: pp. 606-607

TOP: Mechanisms that control pH of body fluids

35. Acidosis in the blood begins to occur when the pH falls below 6.8.

ANS: F PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances

36. If the buffer pair is to function properly, there must be 10 times more NaHCO3 than there is H2CO3.

ANS: F PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances

37. If the buffer pair is to function properly, there must be 20 times more H2CO3 than there is NaHCO3

ANS: F PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances

38. If the buffer pair is to function properly, there must be 20 times more NaHCO3 than there is H2CO3

ANS: T PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances

39. Hyperventilation syndrome can cause metabolic alkalosis.

ANS: F PTS: 1 DIF: Memorization

REF: pp. 607-608 TOP: pH imbalances

40. Excessive vomiting can cause metabolic alkalosis.

ANS: T PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances

41. A sustained drop in breathing rate can cause respiratory acidosis.

ANS: T PTS: 1 DIF: Memorization

REF: p. 608 TOP: pH imbalances

42. A prolonged period of uncontrolled diabetes would have the same effect on the blood pH as a prolonged period of depressed breathing rate.

ANS: T PTS: 1 DIF: Application REF: p. 607 TOP: pH imbalances

43. A prolonged period of gastric suctioning would have the same effect on the blood pH as a prolonged period of uncontrolled diabetes.

ANS: F PTS: 1 DIF: Application REF: p. 607 TOP: pH imbalances

44. A person with only 10 times more NaHCO3 than H2CO3 is in a condition called uncompensated metabolic acidosis.

ANS: T PTS: 1 DIF: Memorization

REF: p. 610 TOP: pH imbalances

45. A person with only 10 times more H2CO3 than NaHCO3 is in a condition called uncompensated metabolic acidosis.

ANS: F PTS: 1 DIF: Application REF: p. 610 TOP: pH imbalances

46. Metabolic acidosis is compensated with the loss of enough NaHCO3 to bring the ratio back up to 20 times more H2CO3.

ANS: F PTS: 1 DIF: Memorization

REF: p. 610 TOP: pH imbalances

47. The lung can remove the equivalent of 50 L of carbonic acid a day.

ANS: F PTS: 1 DIF: Memorization

REF: p. 603 TOP: Mechanisms that control pH of body fluids

48. Blood in the pulmonary artery has a higher pH than blood in the pulmonary vein.

ANS: F PTS: 1 DIF: Application REF: p. 606

TOP: Respiratory mechanism of pH control

49. The urine can have an H+ concentration 100 times higher than the concentration in the blood.

ANS: T PTS: 1 DIF: Application REF: p. 606 TOP: Urinary mechanism of pH control

50. A person can develop acidosis of the blood even if the pH is above 7.

ANS: T PTS: 1 DIF: Memorization

REF: p. 607 TOP: pH imbalances