Explain why there where changes in tidal volume, FVC, FEV1 and FEV1/FVC in the various patients and in the individuals exercising.
My response so far. Correct me if I'm wrong or add anything if I'm missing important details.
Patients who suffer from emphysema and asthma show decreased FVC, FEV1 and FEV1/FVC compared to normal patients. These are obstructed disorders that lead to airways collapsing, making it harder to expire upon inspiration. The reduced airway radius, and thus increased resistance, restricts the amount of air that can be expired after each tidal volume. Compared to emphysema patients who have normal tidal volume, the tidal volume of asthmatic patients is decreased partly due to this bronchoconstriction. An asthmatic patient that is supplied with an inhaler regains but falls just short of the normal values for these measurements, but achieves the same FEV1/FVC value. This inhaler induces bronchodilation by relaxing the smooth muscle that innervates these bronchioles, and so airway resistance is decreased, facilitating normal forced expiration. During moderate and heavy exercise, the tidal volume increases due to the increases in metabolic demands. The FVC stays the same but the FEV1 decrease/increase because..? and so the FEV1/FVC decrease/increase because...?
Thanks in advance.
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