22B Notes

What is intrapleural pressure?
A. Pressure inside the alveoli
B. Pressure in the pleural cavity
C. Pressure in the trachea
D. Atmospheric pressure

Pressure in the pleural cavity

Why is intrapleural pressure normally negative?
A. Because lungs are filled with air
B. Because of opposing lung recoil and chest wall pull
C. Because of high atmospheric pressure
D. Because of surfactant

Because of opposing lung recoil and chest wall pull

What is the main function of negative intrapleural pressure?
A. To compress alveoli
B. To keep lungs expanded against chest wall
C. To increase airway resistance
D. To reduce oxygen levels

To keep lungs expanded against chest wall

Transpulmonary pressure is:
A. Alveolar pressure minus atmospheric pressure
B. Intrapleural pressure minus alveolar pressure
C. Intrapulmonary pressure minus intrapleural pressure
D. Atmospheric pressure minus lung pressure

Intrapleural pressure minus alveolar pressure

Boyle’s law states that:
A. Pressure increases as volume increases
B. Pressure decreases as temperature increases
C. Pressure and volume are inversely related
D. Volume stays constant in the lungs

Pressure and volume are inversely related

During inspiration, thoracic volume:
A. Decreases
B. Increases
C. Stays the same
D. Becomes zero

Increases

During inspiration, intrapulmonary pressure:
A. Increases above atmospheric
B. Decreases below atmospheric
C. Stays equal to intrapleural pressure
D. Becomes positive

Decreases below atmospheric

Air flows into the lungs because:
A. Pressure in lungs is higher than atmosphere
B. Oxygen actively enters lungs
C. Air moves from high to low pressure
D. Muscles push air in

Air moves from high to low pressure

Quiet inspiration is:
A. Passive
B. Active
C. Random
D. Chemical

Active

The diaphragm during inspiration:
A. Relaxes and moves up
B. Contracts and flattens
C. Becomes rigid
D. Stops moving

Contracts and flattens

External intercostal muscles during inspiration:
A. Depress ribs
B. Raise ribs
C. Close alveoli
D. Contract trachea

Raise ribs

Quiet expiration occurs because:
A. Muscles contract
B. Lungs recoil passively
C. Diaphragm contracts
D. Air is pushed in

Lungs recoil passively

Air moves in and out of lungs due to:
A. Oxygen diffusion only
B. Pressure gradients
C. Blood pumping
D. Gravity

Pressure gradients

Alveolar ventilation is important because it measures:
A. Total air in lungs
B. Air reaching gas exchange areas
C. Air in trachea
D. Air in nose only

Air reaching gas exchange areas

Rapid shallow breathing causes alveolar ventilation to:
A. Increase
B. Stay the same
C. Decrease
D. Stop completely

Decrease

The respiratory membrane is important because it:
A. Produces mucus
B. Allows gas exchange
C. Controls breathing rate
D. Produces surfactant

Allows gas exchange

Alveoli are ideal for gas exchange because they:
A. Are thick and strong
B. Have large surface area and thin walls
C. Are filled with cartilage
D. Have no blood supply

Have large surface area and thin walls

Surfactant functions to:
A. Increase surface tension
B. Decrease surface tension
C. Block oxygen
D. Harden alveoli

Decrease surface tension

Without surfactant:
A. Alveoli collapse
B. Breathing becomes easier
C. Airway resistance decreases
D. Oxygen increases

Alveoli collapse

Pneumothorax is:
A. Fluid in lungs
B. Air in pleural cavity
C. Infection of bronchi
D. Lung expansion

Air in pleural cavity

Atelectasis is:
A. Lung overinflation
B. Lung collapse
C. Increased oxygen flow
D. Surfactant production

Lung collapse

Asthma increases difficulty breathing because it:
A. Increases surfactant
B. Decreases oxygen in blood directly
C. Increases airway resistance
D. Expands alveoli

Increases airway resistance

Tidal volume is:
A. Maximum air in lungs
B. Air exchanged during normal breathing
C. Air left after forced expiration
D. Air in trachea only

Air exchanged during normal breathing

Residual volume is:
A. Air always remaining in lungs
B. Air inhaled during exercise
C. Air in bronchi
D. Air in nose

Air always remaining in lungs

Vital capacity is:
A. Total lung capacity
B. Air in conducting zone
C. Maximum usable air you can exhale after full inhale
D. Air left in alveoli only

Maximum usable air you can exhale after full inhale