mock exam: within peripheral chemoreceptors, the response to a drop in pao2 is greater when a) the central chemoreceptors are also responding do a drop in arterial pao2 b) the central chemoreceptors are responding to an increase in pao2 c) arterial paco2 is also below normal d) arterial paco2 is above normal e) arterial paco2 is normal d) arterial paco2 is above normal e) arterial paco2 is normal there is a cooperative effect on the peripheral chemoreceptors. it is most effective when pao2 is low and paco2 is high