[问答题]
8. A rise in blood pH, caused
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Outline how feedback control mechanisms restore the breathing rate and tidal volume to resting levels while resting after exercise.
参考答案:
Chemoreceptors in brain stem sense the blood $pH/CO_2$concentration
Hypothalamus/brainstem/respiratory centre produce a higher rate of stimulation of
diaphragm and intercostal muscles – to keep breathing rate high.
As blood $pH/CO_2$levels fall closer to normal levels feedback control mechanisms reduce stimulation of diaphragm and intercostal muscles.
Chemoreceptors sense the blood $pH/CO_2$concentration return to normal/set point.
Hypothalamus/brainstem/respiratory centre reduces stimulation of diaphragm and intercostal muscles.
Respiration rate returns to the resting value.
This is an example of Negative feedback (Stimulus of high $CO_2$levels is reduced by the
response, of a higher breathing rate. As $CO_2$levels return to normal the response reduces).
本题详细解析:
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