Pressure in the Lungs and Pleural Cavity - Video Tutorials & Practice Problems

What factor is most important in keeping the lungs from collapsing?

• A. a)   Collagen.
• B. Intrapleural pressure.
• C. Elastin.
• D. Fluid lining the alveoli.

Individuals with COPD (chronic obstructive pulmonary disorder) have degraded elastin protein, causing their lungs to have less recoil. How would this affect intrapleural pressure and why?

• A. Intrapleural pressure would be more negative because less recoil would lead to less inward pull on the pleura.
• B. Intrapleural pressure would be less negative because less recoil would lead to less inward pull on the pleura.
• C. Intrapleural pressure would become positive because less recoil would lead to an outwards push on the pleura.
• D. Intrapleural pressure would become positive because less recoil would lead to less inward pull on the pleura.

True or false: if false choose the answer that best corrects the statement.

In healthy lungs, the intrapulmonary pressure is always lower than the intrapleural pressure.

• A. True.
• B. False, the intrapulmonary pressure is only lower during some parts of ventilation.
• C. False, the intrapulmonary pressure is always greater than the intrapleural pressure.
• D. False, the intrapulmonary and intrapleural must be the same for ventilation to occur.

Pleural effusion is a condition where fluid accumulates in the pleural cavity. Which pressure or pressures would you expect to be most directly impacted by this fluid accumulation?

• A. Intrapleural pressure.
• B. Intrapulmonary pressure.
• C. Both A & B are correct.
• D. Neither pressure would be impacted.