22. The Respiratory System
Pressure in the Lungs and Pleural Cavity
- Open QuestionAs a result of a stroke, Mrs. Minnick's swallowing is uncoordinated. What detrimental effect might this have on her ability to breathe?
- Open QuestionCary hyperventilates for several minutes before diving into a swimming pool. After he enters and begins swimming underwater, he blacks out and almost drowns. What caused this to happen?
- Open QuestionThe contraction of the diaphragm and the external intercostal muscles begins inspiration. What happens, in terms of volume and pressure changes in the lungs, when these muscles contract?
- Open Questiona. Differentiate clearly between minute ventilation and alveolar ventilation rate.b. Which provides a more accurate measure of ventilatory efficiency, and why?
- Open QuestionWhat is the significance of (a) Boyle's law, to the process of respiration?
- Open QuestionWhen the diaphragm and external intercostal muscles contract, (a) exhalation occurs, (b) intrapulmonary pressure increases, (c) intrapleural pressure decreases, (d) the volume of the lungs decreases, (e) the size of the thoracic cavity increases.
- Multiple ChoiceDuring inspiration, air moves into the lungs because __________.
- Open Question
Which of the following does not affect the efficiency of pulmonary gas exchange?
a. The surface area of the respiratory membrane
b. The degree of match of ventilation to perfusion
c. The percent saturation of hemoglobin
d. The thickness of the respiratory membrane
- Multiple ChoiceThe transpulmonary pressure is the difference between the __________ and the __________ pressure.
- Open Question
Which of the following statements about pulmonary ventilation is false?
a. Normal expiration requires the use of the expiratory muscles to decrease lung volume.
b. The inspiratory muscles increase lung volume, which decreases intrapulmonary pressure.
c. For inspiration to occur, intrapulmonary pressure must decrease below atmospheric pressure.
d. The intrapleural pressure is less than the intrapulmonary pressure; this prevents the lungs from collapsing during expiration.
- Open Question
Match each term with the correct definition
____Airway resistance
____Surface tension
____Surfactant
____Pulmonary compliance
____V/Q ratio
a. A detergent-like chemical secreted by bronchial smooth muscle that reduces surface tension
b. The matching of ventilation to perfusion
c. Largely determined by the diameter of the airways
d. Caused by the formation of hydrogen bonds between water molecules
e. Determined by the surface tension of the alveoli, the elastic tissue of the lungs, and the condition of the chest wall
- Open Question
If you swallow a large bite of food without properly chewing it first, you will feel discomfort during ventilation. Explain this, considering the arrangement of the trachea and the esophagus.
- Multiple ChoiceWhat type of pressure keeps the air spaces in the lungs open?
- Multiple Choice
What factor is most important in keeping the lungs from collapsing?
- Open Question
Predict what would happen to the tidal volume and inspiratory reserve volume if the phrenic nerves were severed. Which muscles would contract to try to compensate for this?