front 1 Cutting the phrenic nerves will result in what?
| back 1 B)paralysis of the diaphragm |
front 2 Which of the following laryngeal cartilages is/are not paired?
| back 2 A)epiglottis
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front 3 Under ordinary circumstances, the inflation reflex is initiated by
| back 3 C)overinflation of the alveoli and bronchioles |
front 4 The detergent-like substance that keeps alveoli from collapsing between breaths because it reduces surface tension of the water film in the alveoli is called what?
| back 4 C)Surfactant |
front 5 What determines the direction of gas movement?
| back 5 B)partial pressure gradient |
front 6 When the inspiratory muscles contract
| back 6 C)the volume of the thoracic cavity decreases |
front 7 The nutrient blood supply of the lungs is provided by what?
| back 7 D)the bronchial arteries |
front 8 Oxygen and carbon dioxide are exchanged in the lungs and through all cell membranes by what?
| back 8 B)Diffusion |
front 9 Which of the following would not normally be treated by 100% oxygen therapy?
| back 9 C)respiratory crisis in an emphysema patient and eupnea
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front 10 Most Oxygen carried in the blood is
| back 10 C)Chemically combined with the heme in red blood cells |
front 11 Which of the following has the greatest stimulating effect on the respiratory centers in the brain?
| back 11 B)Carbon dioxide |
front 12 In mouth to mouth artificial respiration, the rescuer blows air from his or her own respiratory system into that of the victim. Which of the following is correct?
| back 12 B)1, 2, 4 |
front 13 A baby holding its breath will
| back 13 B)automatically start to breathe again when the carbon dioxide levels in the blood reach a high enough value |
front 14 Under ordinary circumstances which of the following blood components is of no physiological significance?
| back 14 C)Nitrogen |
front 15 Damage to which of the following would most likely result in cessation of breathing?
| back 15 B)the ventral respiratory group of the medulla |
front 16 The bulk of carbon dioxide is carried
| back 16 B)as the ion HCO3- in the plasma after first entering the red blood cell |
front 17 Trace the route of air from the external nares to the alveolus. Name subdivisions, of organs where applicable, then, differentiate between conducting and respiratory zone structures. | back 17 The route of air from the external nares to an alveolus and the organs involved are as follows: conducting zone structures—external nares, nasal cavity, pharynx (nasopharynx, oropharynx, laryngopharynx), larynx, trachea, and right and left primary bronchi, secondary bronchi, tertiary bronchi and successive bronchi orders, bronchioles, and terminal bronchioles; respiratory zone structures—respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli. (pp. 805–816) |
front 18 a) Why is it important that the trachea is reinforced with cartilage rings?
| back 18 a. The trachea is reinforced with cartilage rings to prevent the trachea from collapsing and to keep the airway patent despite the pressure changes that occur during breathing.
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front 19 Briefly explain the reasons that men have deeper voices than boys or women. | back 19 The adult male larynx as a whole is larger and the vocal cords are longer than those of women or boys. These changes occur at puberty under the influence of rising levels of testosterone. (p. 808) |
front 20 The lungs are mostly passageways and elastic tissue. a) what is the role of the elastic tissue?
| back 20 a. The elastic tissue is essential both for normal inspiration and expiration; expiration is almost totally dependent on elastic recoil of the lungs when the inspiratory muscles relax. (p. 819)
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front 21 Describe the functional relationships between volume changes and gas flow into and out of the lungs. | back 21 The volume of gas flow to and from the alveoli is directly proportional to the difference in pressure between the external atmosphere and the alveoli. Very small differences in pressure are sufficient to produce large volumes of gas flow. As thoracic volume increases, intrapulmonary pressure decreases, resulting in air flow into the lungs. When the lungs recoil, thoracic volume decreases, causing intrapulmonary pressure to increase, and gases flow out of the lungs. (p. 820) |
front 22 Discuss how airway resistance, lung compliance, and alveolar surface tension influence pulmonary ventilation. | back 22 Pulmonary ventilation, or gas flow into and out of the lungs, relies on the pressure gra-dient between the atmosphere and alveoli, and airway diameter. Given that gas flow in a system is equal to the pressure gradient divided by the resistance, when resistance increases, gas flow decreases, and vice versa. Changes in resistance are related to airway diameter, which is greatest in medium-sized bronchi. Lung compliance is based on two factors: distensibility and alveolar surface tension. Distensibility is the degree of stretch possible in the lung tissue, while alveolar surface tension is related to the collapsing force of water vapor within the alveoli. Surfactant is secreted in the alveoli to optimize surface tension. In terms of lung compliance, the greater the volume increase for a given rise in pressure, the greater the compliance. (pp. 820–821) |
front 23 a) Differentiate clearly between minute respiratory voloume and alveolar ventilation rate?
| back 23 a. Minute ventilation is the total amount of gas that flows into and out of the respiratory tract in one minute. Alveolar ventilation rate takes into account the amount of air wasted in dead space areas and provides a measurement of the concentration of fresh gases in the alveoli at a particular time.
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front 24 State Dalton’s law of partial pressure and Henry’s law | back 24 Dalton’s law of partial pressures states that the total pressure exerted by a mixture of gases is the sum of the pressure exerted independently by each gas in the mixture. Henry’s law states that when a mixture of gases is in contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure and its solubility in the liquid. (p. 824) |
front 25 a) Define hyperventilation.
| back 25 a. Hyperventilation is rapid or deep breathing.
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front 26 Describe age-related changes in respiratory function. | back 26 Age-related changes include a loss of elasticity in the lungs and a more rigid chest wall. These factors result in a slowly decreasing ability to ventilate the lungs. Accompanying these changes is a decrease in blood oxygen levels and a reduced sensitivity to the stimulating effects of carbon dioxide. (p. 842) |
front 27 Critical Thinking
| back 27 Hemoglobin is almost completely (98%) saturated with oxygen in arterial blood at normal conditions. Hence, hyperventilation will increase the oxygen saturation very little, if at all. However, hyperventilation will flush CO2 out of the blood, ending the stimulus to breathe and possibly causing (1) cerebral ischemia due to hypocapnia, and (2) O2 decrease to dangerously low levels, resulting in fainting. (p. 828) |
front 28 Critical Thinking
| back 28 a. The lung penetrated by the knife collapsed because the intrapleural pressure became equal to the atmospheric pressure, allowing the pleural membranes to separate.
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front 29 Critical Thinking
| back 29 Adjacent bronchopulmonary segments are separated from one another by partitions of dense connective tissue, which no major vessels cross. Therefore, it is possible for a surgeon to dissect adjacent segments away from one another. The only vessels that had to be cauterized were the few main vessels to each bronchopulmonary segment. (p. 814) |
front 30 Critical Thinking
| back 30 Mary Ann is suffering from decompression sickness, brought on by the rapid ascent in the plane. During the week of diving, she accumulated nitrogen gas in her tissues that at normal altitudes leaves her tissues slowly and unnoticed. However, on the flight, cabin pressure decreased quickly enough to allow residual nitrogen gas to leave more rapidly, causing her symptoms. The return to a lower altitude with a higher atmospheric pressure upon landing alleviates her symptoms. (p. 825) |