phagocytic defense in the normal lung is shared principally by two kinds of cells - alveolar macrophages that reside on the air surface and roam the alveoli and pmns that circulate in the intravascular space or are stored transiently in areas adjacent to the capillary-alveolar interface ( marginated in capillaries ) and can reach the alveolar space quickly .
C0085236
alveolar macrophages
C1515933
alveoli