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09mohamf 09mohamf
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12 years ago
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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wrote...
Donated
Trusted Member
12 years ago
Is this a question in the physioEx exercise activity?
09mohamf Author
wrote...
12 years ago
This is not a direct question from the activity worksheet but it is related to the results I obtained from doing the the exercise. Its a question that i need to put in my discussion session for my lab report. I can't come up witH an explanation as to why during moderate be heavy exercise the FEV1 and the FEV1/FVC decreased. Thanks in advance!
wrote...
Staff Member
12 years ago
Tidal volume increases over normal breathing with both moderate and heavy exercise simple because the respiratory rate is much higher during heavy exercise. Furthermore, FVC measures the amount of gases expelled when a subject takes a deep breath and then forcefully exhales maximally and as rapidly as possible; once again, exercise plays a role in this measurement. FEV1 determines the amount of air expelled during the first second.

To be honest 09mohamf, I haven't done these studies so this is all I got. Frowning Face
- Master of Science in Biology
- Bachelor of Science
09mohamf Author
wrote...
12 years ago
Yeah I just don't know how to explain why these values change.

Due to increases in metabolic demands, tidal volume increases during moderate and heavy exercise, making use of both inspiratory and expiratory reserve. Absolute values of FEV1 and FEV1/FVC decreased after exercise, but there was no significant difference in FVC. A weakness in of expiratory muscles leads to a quick fall in the expiratory ability. This lowers FEV1/FVC percentage even without the obstruction of airways. There is also an increase in respiratory rate which can be linked to hyperventilation. This hyperventilation results in a decrease ratio of CO2 production to alveolar ventilation.

This is what I came up with and still it doesn't seem like i get straight to the point. Confounded Face
rjones53
wrote...
12 years ago
Yeah I just don't know how to explain why these values change.

Due to increases in metabolic demands, tidal volume increases during moderate and heavy exercise, making use of both inspiratory and expiratory reserve. Absolute values of FEV1 and FEV1/FVC decreased after exercise, but there was no significant difference in FVC. A weakness in of expiratory muscles leads to a quick fall in the expiratory ability. This lowers FEV1/FVC percentage even without the obstruction of airways. There is also an increase in respiratory rate which can be linked to hyperventilation. This hyperventilation results in a decrease ratio of CO2 production to alveolar ventilation.

This is what I came up with and still it doesn't seem like i get straight to the point. Confounded Face

Sounds like a thorough answer though...
Biology!
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