Jijiyar alveolar wani ƙaramin jigon jini ne wanda ke ba da jini mai iskar oxygen zuwa alveoli, waɗanda ƙananan buhunan iska ne a cikin huhu inda musayar iskar gas ke gudana tsakanin iska da magudanar jini. Kalmar "alveolar" ta fito ne daga kalmar Latin "alveolus," wanda ke nufin "ƙananan rami," kuma kalmar "jijiya" tana nufin jigon jini wanda ke dauke da jinin oxygen daga zuciya zuwa kyallen jikin jiki. Saboda haka, jijiyoyin alveolar wani muhimmin sashi ne na zagayawa na huhu, wanda ke isar da jinin oxygen zuwa huhu kuma yana cire carbon dioxide.