Alveolar Macrophage are called Dust cells
Dust cells contain numerous secondary lysosomes and lipid droplets.
They phagocyte and remove unwanted materials such as inhaled particulate matter (carbon), dust, and bacteria.
Dust cells are present free within alveolar spaces and some in inter-alveolar septa (spaces)
Dust cells – first line of defense against invading respiratory pathogens.
Cells in Alveoli
Alveoli are comprised of three different kinds of cells:
(1) Type I pneumocytes – build up the structure of the alveolar wall and aid in respiration.
They do not replicate.
(2) Type II pneumocytes – secrete a lipoprotein called surfactant that prevents the collapse of the alveoli even after exhalation.
(3) Alveolar macrophages or Dust cells – produce a variety of signaling chemicals that interact with other cells of the immune system to orchestrate a response that maintains immunologic and tissue homeostasis in the body.
Type II pneumocytes replete both types of pneumocytes and AMs which in turn are vital to host defenses and tissue remodeling