Question | Answer |
For carbon dioxide levels to remain constant during exercise, which of the following factors must be elevated? | alveolar ventilation |
A lung that loses elastic fibers (as in emphysema) would exhibit which of the following characteristics? | increased pulmonary compliance |
Which of the following ventilatory patterns would result in the greatest ventilation per minute (assume constant dead space)? | 8 840 |
4. Question : According to Poiseuille's law, which of the following statements are true if we wish to maintain a constant flow of gases? | Halving the tube radius will require a 16-time increase in driving pressure. |
Which of the following factors would tend to increase the elastic component of the work of breathing? | decreased compliance of the lungs or thorax and increased VT |
What is ventilation that is insufficient to meet metabolic needs called? | hypoventilation |
What happens during normal inspiration? | I.The Ppl decreases further below atmospheric. II.The transpulmonary pressure gradient widens. III.Palv drops below that at the airway opening. |
Regional factors affecting the distribution of gas in the normal lung result in which of the following? | More ventilation goes to the bases and lung periphery. |
What term is used to note the difference between inspiratory lung volume and expiratory lung volume at any given pressure? | hysteresis |
A fibrotic lung would exhibit which of the following characteristics? | decreased lung compliance |
What is the single best indicator of the adequacy or effectiveness of ventilation? | PaCO2 |
Which of the following statements about alveolar pressure (Palv) during normal quiet breathing is true? | It is negative during inspiration and positive during expiration. |
All of the following will cause an increase in the pressure energy required for inspiration EXCEPT which one? | increased compliance |
In healthy individuals, what may lead to airway collapse? | forced exhalation to RV |
What is the primary function of the lungs? | gas exchange |
How is compliance computed? | change in volume/change in pressure |
Which of the following formulas is used to compute the mechanical work of breathing? | change in pressure x change in volume |
Which of the following ventilatory patterns would result in the MOST wasted ventilation per minute (assume constant physiologic dead space)? | 30 170 |
In what portion of the lungs does alveolar dead space normally occur? | apices |
In a normal individual lying on the right side (right side down), which of the following conditions would be true? | The right lung would receive the most ventilation. |
Which of the following diseases or disorders is most likely to result in an increased VD/VT ratio? | pulmonary embolus |
During normal inspiration, which of the following occurs? | Alveoli at the apexes expand less than those at the bases |
For healthy individuals at rest, which of the following statements about exhalation is true? | Exhalation will be passive, due to inspiratory stored potential energy. |
How can the body effectively compensate for an increased VDphy? | increased tidal volume |
During expiration, why does gas flow out from the lungs to the atmosphere? | Palv is greater than at the airway opening. |