21.3A Pulmonary Ventilation Flashcards
What drives movement of air molecules during inspiration and exploration?
Pulmonary ventilation depends on pressure gradients that drive inspiration and expiration.
What are the three pressure gradients that influence pulmonary ventilation?
- atmospheric pressure
- intrapulmonary pressure
- intrapleural pressure
What is Atmospheric pressure vs. intrapulmonary pressure vs. Intrapleural pressure?
- Atmospheric pressure – molecules that make up air are subject to the force of gravity
- Intrapulmonary pressure – air pressure within alveoli
- Intrapleural pressure – pressure found within pleural cavity
What are the three physical factors determine the effectiveness of pulmonary ventilation?
Airway resistance is the impedance to air flow, and it decreases the effectiveness of pulmonary ventilation.
Alveolar surface tension is the attraction created by hydrogen bonding between water molecules that tends to collapse the alveoli. Surfactant reduces alveolar surface tension.
Pulmonary compliance refers to the ability of the lungs to stretch. If pulmonary compliance decreases, the effectiveness of pulmonary ventilation decreases.
Surfactant ________ alveolar surface tension.
Alveolar surface tension is the attraction created by hydrogen bonding between water molecules that tends to collapse the alveoli. Surfactant reduces alveolar surface tension.
Air moves out of the lungs when the pressure inside the lungs is __________.
A. greater than atmospheric pressure
B. less than atmospheric pressure
C. equal to atmospheric pressure
D. less than intrapleural pressure
Air moves out of the lungs when the pressure inside the lungs is __________.
Answer:A. greater than atmospheric pressure
What primarily determines airway resistance in the respiratory passageways?
A. diameter of the conducting zone passageways
B. elasticity of the lung tissues
C. degree of alveolar surface tension
D. presence of surfactant
What primarily determines airway resistance in the respiratory passageways?
Answer: A. diameter of the conducting zone passageways
Predict what happens to air movement when atmospheric pressure is 760 mm Hg, intrapulmonary pressure is 758 mm Hg, and intrapleural pressure is 754 mm Hg.
exhalation
atelectasis
inhalation
no air movement
Predict what happens to air movement when atmospheric pressure is 760 mm Hg, intrapulmonary pressure is 758 mm Hg, and intrapleural pressure is 754 mm Hg.
Answer: C. inhalation
What reduces friction around the lungs as they expand and contract?
surfactant
pleural fluid
synovial fluid
mucus
What reduces friction around the lungs as they expand and contract?
Answer: B. pleural fluid
The volume that remains in the lungs after a forced expiration is the __________.
dead space volume
vital capacity
functional residual capacity
residual volume
The volume that remains in the lungs after a forced expiration is the __________.
Answer: D residual volume
