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.
A pilus (Latin for 'hair'; plural: pili) is a hairlike appendage found on the surface of many bacteria. The terms pilus and fimbria (Latin for 'fringe'; plural: fimbriae) can be used interchangeably, although some researchers reserve the term pilus for the appendage required for bacterial conjugation.All pili are primarily composed of oligomeric pilin proteins. Dozens of these structures can exist on the bacteria.ome pili, called type IV pili, generate motile forces. The external ends of the pili adhere to a solid substrate, either the surface to which the bacteria are attached or to other bacteria, and when the pilus contracts, it pulls the bacteria forward, like a grappling hook.