refers to physicological responses that match airflow to blood flow and vice versa
poor ventilation leads to a low PO2 (decreased pressure in blood vessels) in that region of the lung, this stimulates local vasoconstriction, rerouting the blood to better-ventilated areas of the lung.
increased ventilation (increased air flow) raises PO2 and stimulates vasodilation, increasing blood flow to that region to take advantage of the oxygen availability
- for CO2
- decreased blood flow leads to reduced PCO2 inthe alveoli, so constriction of the broncioles, leads to decreased airflow, could lead to a blood clot
increased blood flow leads to elevated PCO2 in alveoli, so dilitation of bronchioles, increased air flow, redirected blood flow