If pressure from outside the lungs causes atelectasis, your doctor will treat the cause of the pressure. For example, if the cause is a tumor or fluid buildup, your doctor will remove the tumor or fluid. This will allow your lung to fully expand. Atelectasis Caused by a Blockage
Pilus. Definition. noun, plural: pili. (microbiology) Short, filamentous projection on a bacterial cell, used not for motility but for adhering to other bacterial cell (especially for mating) or to animal cells. Supplement. Bacterial pili are involved in cell adhesion.
Pili are involved in the process of bacterial conjugation where they are called conjugation pili or sex pili. Type IV pili (non-sex pili) also aid bacteria in gripping surfaces.Pili are absent in gram-positive bacteria and present in gram-negative bacteria.