6/16/Quiz

Which of the following best describes what happens to lung compliance during normal inhalation?

• Lung compliance increases because the lungs expand more easily as they fill with air

• Lung compliance decreases because it becomes harder to expand the lungs as they fill

• Lung compliance remains constant because the lungs are passive during breathing

• Lung compliance is irrelevant to inhalation; it only applies during exhalation

Which of the following best explains the phenomenon of hysteresis in the lung pressure-volume curve?

• The lungs fill and empty with the same amount of pressure at each volume point

• Hysteresis refers to the delay in oxygen diffusion during alveolar gas exchange

• Hysteresis shows that lung compliance is always greater during inspiration than expiration

• More pressure is required to inflate the lungs than to deflate them due to surface

How does the Law of Laplace explain the importance of pulmonary surfactant?

• It shows that without surfactant, smaller alveoli would collapse due to higher pressure

• It shows that larger alveoli are more likely to collapse due to increased surface tension

• It shows that alveolar pressure is unaffected by surface tension or radius

• It shows that surface tension has no role in the stability of alveolar structures

In a patient with pulmonary fibrosis, how would the lung volume vs. pressure curve change compared to a healthy individual?

• The slope of the curve becomes steeper, indicating increased lung compliance

• The slope of the curve flattens, indicating decreased lung compliance

• The curve shifts upward and to the left, showing improved lung elasticity

• The curve remains unchanged because fibrosis affects only gas exchange, not compliance

How would the lung volume vs. pressure curve change in a patient with COPD (e.g., emphysema) compared to a healthy individual?

• The slope becomes flatter, indicating decreased lung compliance due to stiff lungs

• The curve shifts downward and to the left, reflecting improved elastic recoil

• The slope becomes steeper, indicating increased compliance due to loss of elastic recoil

• The curve becomes more linear, showing reduced airway resistance

A healthy 19-year-old suddenly feels sharp chest pain and can’t catch his breath. He was just standing when it happened. No injury. What type of pneumothorax is this?

• Open

• Closed

• Tension

A man gets stabbed in the chest and is struggling to breathe. You notice his neck veins are bulging and his trachea is pushed to the other side. What type of pneumothorax is this?

• Open

• Closed

• Tension

A worker falls onto a sharp object that pierces his chest. With every breath, you hear a sucking sound from the wound. What type of pneumothorax is this?

• Open

• Closed

• Tension

Why is the partial pressure of oxygen (PO₂) lower in the alveoli than in the air entering the airways?

• Because oxygen is completely absorbed before reaching the alveoli

• Because oxygen is converted to carbon dioxide in the alveoli

• Because the alveoli have less surface area than the airways

• Because the air is humidified and mixed with leftover carbon dioxide in the alveoli

Why does pulmonary vascular resistance increase, and blood flow decrease when alveolar PO₂ (PAO₂) is low?

• Low oxygen causes the pulmonary vessels to dilate, reducing pressure

• Low oxygen causes pulmonary vasoconstriction to redirect blood to better-ventilated areas

• The body redirects blood to poorly ventilated alveoli to increase oxygen uptake

• High carbon dioxide levels cause the vessels to collapse completely

Tags

NGSS.HS-LS1-3