Question: What Happens During Respiration?
Answer: The process of respiration involves two major processes: inspiration and expiration.
During inspiration, the inspiratory muscles contract, the diaphragm descends, and the rib cage rises. The thoracic cavity volume increases, stretching the lungs, and the intrapulmonary volume increases. This causes the intrapulmonary pressure to drop. Air flows into the lungs until the intrapulmonary pressure equals the atmospheric pressure.
During expiration, the inspiratory muscles relax, the diaphragm rises, and the rib cage descends. The thoracic cavity volume decreases, causing the the lungs to recoil, and the intrapulmonary volume decreases. This causes the intrapulmonary pressure to rise, and the air flows out of the lungs until the intrapulmonary pressure equals the atmospheric pressure.
Pulmonary Function Tests can be used to measure how well the lungs take in and expel air and how efficiently they transfer oxygen.
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