Histologic sections of lung tissue from 66-year-old woman, Sheena with congestive heart failure and progressive breathing problems reveal numerous hemosiderin-laden cells within the alveoli. Which of the following is the cell of origin of these “heart failure cells”?

• Example of tissue macrophages are Kupffer cells (liver), alveolar macrophages (lung), osteoclasts (bone), Langerhan’s cells (skin), microglial cells (central nervous system) • In the lung, alveolar macrophages can phagocytose the red blood cells that accumulate in alveoli in individuals with congestive heart failure. These cells contain hemosiderin and are referred to as “heart failure cells.”