Which statement best describes the effect of inspiratory muscle contraction on thoracic volume and intrapulmonary pressure?

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Multiple Choice

Which statement best describes the effect of inspiratory muscle contraction on thoracic volume and intrapulmonary pressure?

During inspiration, the inspiratory muscles contract to enlarge the thoracic cavity. This expansion increases thoracic volume, and as the chest wall and lungs pull outward, the pressure inside the lungs (intrapulmonary or alveolar pressure) falls below atmospheric pressure. The drop in alveolar pressure creates a pressure gradient that pulls air into the lungs. So the best description is that inspiratory muscle contraction increases thoracic volume and decreases intrapulmonary pressure.

During inspiration, the inspiratory muscles contract to enlarge the thoracic cavity. This expansion increases thoracic volume, and as the chest wall and lungs pull outward, the pressure inside the lungs (intrapulmonary or alveolar pressure) falls below atmospheric pressure. The drop in alveolar pressure creates a pressure gradient that pulls air into the lungs. So the best description is that inspiratory muscle contraction increases thoracic volume and decreases intrapulmonary pressure.

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