Which of the Following Is Most Responsible for Keeping the Lung

Multiple Choice

Which of the following is most responsible for keeping the lung surface and the thoracic wall from separating?

A) the presence of surfactant
B) the negative pressure in the alveolar space
C) the force exerted by the external intercostal muscles
D) subatmospheric intrapleural pressure
E) alveolar pressure is higher than atmospheric pressure