Copyright © 2019, Elsevier Inc. All Rights Reserved. 1Chapter 35: Structure and Function of the Pulmonary SystemMcCance/Huether: Pathophysiology: The Biologic Basis of Disease in Adults and Children, 8th EditionMULTIPLE CHOICE 1. What pulmonary defense mechanism propels a mucous blanket that entraps particles moving toward the oropharynx?a. Nasal turbinatesb. Alveolar macrophagesc. Ciliad. Irritant receptors on the naresANS: CThe submucosal glands of the bronchial lining produce mucus, contributing to the mucous blanket that covers the bronchial epithelium. The ciliated epithelial cells rhythmically beat this mucous blanket toward the trachea and pharynx, where it can be swallowed or expectorated by coughing. Mucous is not propelled by nasal turbinates, alveolar macrophages, or irritant receptors.PTS: 1 DIF: Cognitive Level: Remembering 2. Which term is used to identify the movement of gas and air into and out of the lungs?a. Perfusionb. Ventilationc. Respirationd. DiffusionANS: BVentilation is the term used to identify the mechanical movement of gas or air into and out of the lungs. Perfusion is the term used to describe blood that reaches the alveoli. Respiration is the exchange of gasses. Diffusion is the movement of particles through a semipermeable membrane from an area of higher concentration to an area of lower concentration.PTS: 1 DIF: Cognitive Level: Remembering 3. When an individual aspirates food particles, where would the healthcare professional expect to hear decreased or absent breath sounds?a. Left lungb. Right lungc. Trachead. CarinaANS: BThe right mainstem bronchus extends from the trachea more vertically than the left main bronchus; therefore aspirated fluids or foreign particles tend to enter the right lung rather than into the left lung, trachea, or carina.PTS: 1 DIF: Cognitive Level: Remembering 4. Air passage among alveoli is collateral and evenly distributed because of the function of which structures?a. Type I alveolar cellsb. Pores of Kohnc. Acinus poresd. Alveolar poresANS: BTiny passages called pores of Kohn permit some air to pass through the septa from alveolus to alveolus, promoting collateral ventilation and even distribution of air among the alveoli. Type I alveolar cells provide structure to the alveoli. The acinus is the conducting airways that terminate in the respiratory bronchioles, alveolar ducts, and alveoli. Alveolar pores would be the same as the pores of Kohn.PTS: 1 DIF: Cognitive Level: Remembering 5. Where in the lung does gas exchange occur?a. Tracheab. Segmental bronchic. Alveolocapillary membraned. Main bronchusANS: CGas exchange occurs only across the alveolocapillary membrane.PTS: 1 DIF: Cognitive Level: Remembering 6. Surfactant produced by type II alveolar cells facilitates alveolar distention and ventilation by which mechanism?a. Decreasing thoracic complianceb. Attracting water to the alveolar surfacec. Decreasing surface tension in the alveolid. Increasing surface tension in the alveoliANS: CSurfactant, a lipoprotein produced by type II alveolar cells, has a detergent-like effect that separates the liquid molecules, thereby decreasing alveolar surface tension. Surfactant does not decrease thoracic compliance, attract water to the alveolar surface, or increase surface tension in the alveoli.PTS: 1 DIF: Cognitive Level: RememberingCopyright © 2019, Elsevier Inc. All Rights Reserved. 2 7. Which part of the brainstem provides basic automatic rhythm of respiration by sending efferent impulses to the diaphragm and intercostal muscles?a. Dorsal respiratory group (DRG)b. Ventral respiratory group (VRG)c. Pneumotaxic centerd. Apneustic centerANS: BThe basic automatic rhythm of respiration is set by the VRG, a cluster of inspiratory nerve cells located in the medulla that sends efferent impulses to the diaphragm and inspiratory intercostal muscles. The DRG, also located in the medulla, receives afferent impulses from peripheral chemoreceptors in the carotid and aortic bodies; from mechanical, neural, and chemical stimuli; and from receptors in the lungs, and it alters breathing patterns to restore normal blood gases.The pneumotaxic center and apneustic center, situated in the pons, do not generate primary rhythm, but rather act as modifiers of the rhythm established by the medullary centers.PTS: 1 DIF: Cognitive Level: Remembering 8. Which structures secrete surfactant?a. Type I alveolar cellsb. Type II alveolar cellsc. Alveolar macrophagesd. Stretch receptorsANS: BTwo major types of epithelial cells appear in the alveolus. Type I alveolar cells provide structure, and type II alveolar cells secrete surfactant, a lipoprotein that coats the inner surface of the alveolus and facilitates its expansion during inspiration, lowers alveolar surface tension at end expiration, and thereby prevents lung collapse. Neither alveolar macrophages nor stretch receptors secrete surfactant.PTS: 1 DIF: Cognitive Level: Remembering 9. Which describes the pressure in the pleural space?a. Atmosphericb. Below atmosphericc. Above atmosphericd. VariableANS: BPressure in the pleural space is usually negative or subatmospheric (-4 to -10 mmHg).PTS: 1 DIF: Cognitive Level: Remembering 10. A healthcare professional wants to determine the adequacy of a person’s alveolar ventilation. What assessment finding is most important for the professional to consider?a. Respiratory rate of 12 breaths/minb. Ventilatory pattern is regular and rhythmic.c. Respiratory effort is strained with muscle involvement.d. Arterial blood gas shows a PaCO2 of 44 mmHg.ANS: DObservation of the ventilatory rate, pattern, or effort cannot determine the adequacy of alveolar ventilation. If a healthcare professional needs to determine the adequacy of ventilation, then an arterial blood gas analysis must be performed to measure partial pressure of arterial carbon dioxide (PaCO2). The professional would analyze the PaCO2 for this determination.PTS: 1 DIF: Cognitive Level: Applying 11. Which normal physiologic change occurs in the aging pulmonary system?a. Decreased flow resistanceb. Fewer alveolic. Stiffening of the chest walld. Improved elastic recoilANS: CAging decreases chest wall compliance and elastic recoil of the lungs. There is loss of alveolar wall tissue and alveolar enlargement, thus diminishing surface area available for gas diffusion with aging. Aging can also cause the PaO2 to decrease. Vital capacity decreases and residual volume increases;
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