Respiration During Exercise Complete Test Bank Chapter.10

TEST BANK

Chapter 10

RESPIRATION DURING EXERCISE

1. The primary purpose of the pulmonary system is

a. ventilation.

b. to provide an interface for gas exchange.

c. to transport O₂ and CO₂ in the blood.

d. formation of surfactant.

Ans: b

2. The term ventilation refers to the

a. cooling of the airways by respiration.

b. random movement of molecules from an area of high concentration to an area of lower concentration.

c. mechanical process of moving air in and out of the lungs.

d. oxygenation of blood as it travels through the lungs.

Ans: c

3. The most important muscle of inspiration is/are the

a. diaphragm.

b. rectus abdominis.

c. internal oblique.

d. external intercostals.

Ans: a

4. The volume of gas that reaches the respiratory zone (gas-exchange zone) of the lung is termed

a. anatomical dead space.

b. minute ventilation.

c. alveolar ventilation.

d. tidal volume.

Ans: c

5. According to Fick’s law of diffusion, the rate of diffusion for a gas is greater when the surface area for diffusion is large and the “driving pressure” (i.e., partial pressure) between the two sides of tissue is high.

a.

b.

Ans: a

6. In the standing position, blood flow to the base of the lung is ______________ blood flow to the apex.

a. less than

b. the same as

c. greater than

Ans: c

7. Exercise-induced asthma would reduce airflow by

a. lowering the atmospheric pressure.

b. lowering the intrapulmonary pressure.

c. inhibiting action potentials to the diaphragm.

d. increasing airway resistance.

Ans: d

8. Most of the O₂ that is transported in the blood is in

a. a solution as a dissolved gas.

b. the form of oxyhemoglobin.

c. the form of carboxyhemoglobin.

d. the form of deoxyhemoglobin.

Ans: b

9. In general, because of blood hemoglobin concentration differences, males transport less oxygen per unit of blood volume than females.

a.

b.

Ans: b

10. Research demonstrates that respiratory muscle fatigue does not occur during exercise.

a.

b.

Ans: b

11. Myoglobin is a red pigment found in skeletal muscle that serves to

a. transport CO₂ from the cell membrane to the mitochondria.

b. transport O₂ from the cell membrane to the mitochondria.

c. buffer changes in hydrogen ion concentration in the cell.

d. transport O₂ from the mitochondria to the cell membrane.

Ans: b

12. Carbon dioxide is transported in the blood principally as

a. carbaminohemoglobin.

b. dissolved CO₂ in solution in the blood.

c. bicarbonate.

d. carbon monoxide.

Ans: c

13. An increase in alveolar ventilation serves to lower arterial PCO₂ and increase blood pH.

a.

b.

Ans: a

14. Ventilation may drift upward during constant-load submaximal exercise performed in a hot and humid environment due to

a. a lower arterial PO₂.

b. a higher PCO₂.

c. higher blood temperature.

d. all of the above.

Ans: c

15. Exercise-induced hypoxemia that may occur in elite endurance athletes during heavy exercise is likely due to

a. overt lung disease.

b. reduced alveolar ventilation due to exercise-induced asthma.

c. a right-to-left shunt.

d. a diffusion limitation secondary to a rapid red blood cell transit time.

Ans: d

16. The respiratory control center is located in the

a. medulla oblongata.

b. cerebrum.

c. carotid bodies.

d. cerebellum.

Ans: a

17. The carotid bodies are chemoreceptors that are sensitive to changes in arterial

a. H⁺ and K⁺ concentrations.

b. pH, PCO₂, and PO₂.

c. pH and K⁺ concentrations.

d. PO₂ only.

Ans: b

18. The ventilatory central chemoreceptors respond to changes in the

a. pH of mixed venous blood.

b. pH of cerebral spinal fluid.

c. PO₂, pH, and PCO₂ of arterial blood.

d. PCO₂ and H⁺ of mixed venous blood.

Ans: b

19. A decrease in arterial PO₂ below 70 mm Hg would likely result in

a. a decrease in alveolar ventilation.

b. an increase in alveolar ventilation.

c. no change in alveolar ventilation.

Ans: b

20. Under normal conditions, the partial pressure of oxygen in the alveoli is

a. 760 mmHg.

b. 159 mmHg.

c. 105 mmHg.

d. 100 mmHg.

Ans: d

21. The alinear rise in ventilation observed during incremental exercise (i.e., ventilatory threshold) is thought to be principally due to

a. a decrease in arterial PO₂.

b. an increase in arterial PCO₂.

c an increase in arterial pH.

d. a decrease in arterial pH.

Ans: d

22. Activation of rectus abdominis muscles would result in

a. active inspiration.

b. passive inspiration.

c. active expiration.

d. passive expiration.

Ans: c

23. The ideal ventilation-perfusion ratio in the lung is 1.

a.

b.

Ans: a

24. Under normal conditions, the characteristics of arterial blood include

a. PO₂ of 100 mmHg.

b. oxyhemoglobin saturation of 97–98%.

c. oxygen content of 20 ml O₂ / 100 ml blood.

d. all of the above.

Ans: d

25. A by-product of anaerobic glycolysis in red blood cells that is thought to alter the O₂-Hb dissociation curve is

a. lactic acid

b. 2–3 DPG

c. CO₂

d. O₂

Ans: b

26. During exercise at sea level, young, healthy untrained subjects generally maintain exercise arterial PO₂ within

a. 1 mm Hg of resting values.

b. 10–12 mm Hg of resting values.

c. 15–20 mm Hg of resting values.

d. 30–40 mm Hg of resting values.

Ans: b

27. An increase in blood temperature and a decrease in blood pH would result in _____________ in the oxyhemoglobin dissociation curve.

a. a rightward shift

b. a leftward shift

c. no change in

Ans: a

28. At a low PO₂, myoglobin has _______________ affinity for O₂ than hemoglobin.

a. a higher

b. a lower

c. the same

Ans: a

29. The intrapleural pressure is lower than the intrapulmonary pressure.

a.

b.

Ans: a

30. The pulmonary system may limit VO₂ max only in elite endurance athletes.

a.

b.

Ans: b

31. During exercise, more oxygen is unloaded from hemoglobin to the tissues than at rest.

a.

b.

Ans: a

32. Research indicates that nasal strips increase endurance performance.

a.

b.

Ans: b

33. Mitochondrial PO₂ is _____________ capillary PO₂.

a. greater than

b. less than

c. equal to

Ans: b

34. The amount of air inspired and expired at rest is called

a. tidal volume.

b. total lung capacity.

c. vital capacity.

d. residual volume.

Ans: a

35. In a pulmonary function test, a FEV₁/FVC ratio of 0.70 is

a. considered normal.

b. higher than normal.

c. suggestive of airway obstruction.

d. associated with a high VO₂ max.

Ans: c

36. Which of the following is correct?

a. The PO₂ at sea level is 159 mmHg.

b. The percentage of CO₂ in the air is 3.0.

c. The percentage of O₂ in the air at sea level is different from that at altitude.

Ans: a

37. Small changes in arterial PCO₂ have a ______________ effect on ventilation compared to small changes in PO₂.

a. greater

b. lesser

c. the same

Ans: a

38. In response to exercise training, the normal lung

a. increases the number of alveoli.

b. does not undergo measurable changes.

c. decreases anatomical dead space.

d. increases total lung volume.

Ans: b