Pulmonary Physiology I

A healthy 25-year-old medical student participates in a 10-km charity run for the American Heart Association (AHA). Which muscles does the student use (contract) during expiration?

• D) Internal intercostals and abdominal recti
• A) Diaphragm and external intercostals
• B) Diaphragm and internal intercostals
• C) Diaphragm only
• E) Scaleni

Several students are trying to see who can generate the highest expiratory flow. Which muscle is most effective at producing a maximal effort?

• A) Diaphragm
• B) Internal intercostals
• C) External intercostals
• D) Rectus abdominis
• E) Sternocleidomastoid

A preterm infant has a surfactant deficiency. Without surfactant, many of the alveoli collapse at the end of each expiration, which in turn leads to pulmonary failure. Which set of changes is present in the preterm infant compared with a normal infant? (NOTE: ↑ = increased, ↓ = decreased, ↔ = no change)

• D) ↑ Alveolar Surface Tension, ↓ Pulmonary Compliance
• A) ↓ Alveolar Surface Tension, ↓ Pulmonary Compliance
• B) ↓ Alveolar Surface Tension, ↑ Pulmonary Compliance
• C) ↓ Alveolar Surface Tension, ↔ Pulmonary Compliance
• E) ↑ Alveolar Surface Tension, ↑ Pulmonary Compliance

A patient has a dead space of 150 ml, FRC of 3 liters, tidal volume (VT) of 650 ml, expiratory reserve volume (ERV) of 1.5 l, total lung capacity (TLC) of 8 l, and respiratory rate of 15 breaths/min. What is the residual volume (RV)?

• A) 500 ml
• B) 1000 ml
• C) 1500 ml
• D) 2500 ml
• E) 6500 ml

The various lung volumes and capacities include the total lung capacity (TLC), vital capacity (VC), inspiratory capacity (IC), tidal volume (VT), expiratory capacity (EC), expiratory reserve volume (ERV), inspiratory reserve volume (IRV), functional residual capacity (FRC), and residual volume (RV). Which of the following lung volumes and capacities can be measured using direct spirometry without additional methods?

• A
• B
• C
• D
• E

A healthy 10-year-old boy breathes quietly under resting conditions. His tidal volume is 400 ml, and his ventilation frequency is 12/min. Which of the following best describes the ventilation of the upper, middle, and lower lung zones in this boy?

• A
• B
• C
• D
• E

A 30-year-old woman performs a Valsalva maneuver about 30 minutes after eating lunch. Which option best describes the changes in pulmonary and systemic blood volumes that occur in this woman?

• B
• A
• C
• D
• E

A 45-year-old man inhaled as much air as possible and then expired with a maximum effort until no more air could be expired. This action produced the maximum expiratory flow-volume (MEFV) curve shown in the below figure. What is the forced vital capacity (FVC) of this man (in liters)?

• D) 4.5
• A) 1.5
• B) 2.5
• C) 3.5
• E) 5.5

The MEFV curve shown in the above figure is used as a diagnostic tool for identifying obstructive and restrictive lung diseases. At which point on the curve does airway collapse limit maximum expiratory air flow?

• A) A
• B) B
• C) C
• D) D
• E) E

The MEFV curves shown in the above figure were obtained from a healthy person (red curve) and a 57-year-old man with shortness of breath (green curve). The man with shortness of breath likely has which disorder?

• B) Emphysema
• A) Asbestosis
• C) Kyphosis
• D) Scoliosis
• E) Silicosis