12 一位健康者站立且平靜呼吸時，有關肺通氣量（ventilation; V‧A）、血液灌流量（perfusion; Q‧）與肺順應性（lung compliance）之變化，下列敘述何者錯誤？

 肺通氣量：肺尖＜肺底

血液灌流量：肺尖＜肺底

肺通氣量與血液灌流量之比值（V‧A/Q‧）：肺尖＜肺底

肺順應性：肺尖＜肺底

answer is C

The main reason for lower V/Q ratios at the base is that both ventilation and perfusion increase when going from the apex to the base, but Q does it more strongly thus lowering the V/Q ratio. The principal factor involved in the genesis of V/Q dishomogeneity between the apex and the base of the lung is gravity (this is why V/Q ratios change in positions other than the orthostatic one).