<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Bronchodilation involves widening of air passage lumina, typically due to bronchial smooth muscle relaxation, and leads to increased air flow.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>