Studies on epithelial phagocytosis. II.―A method for demonstrating the origin of dust cells

Of all the phagocytic mechanisms of the body that of the lungs for dealing with particulate matter is probably the most widely discussed. As a subject it has been aptly summed up by Drinker and Field (1933) as "exceedingly confused and proportionately confusing." It has long been known that such particles as are not entangled in the ciliary film of mucus of the respiratory tract are taken up by large and characteristic "dust-cells." It is also generally agreed that a similar element, the heart-failure cell of passive pulmonary congestion, is identical with the dust-cell not only in structure and function, but also in origin. For the "heart-failure cell" is likewise a devourer of pigment; not, in this cell, inhaled, but derived from the haemoglobin of red blood corpuscles extravasated through the damaged capillary walls.