Suction is the force that a partial vacuum exerts upon a solid, liquid, or a gas.[1][better source needed] Removing air from a space results in a lowered pressure, which can cause fluids to enter the space or produce adhesion.

When the pressure in one part of a system is reduced relative to another, the fluid in the higher pressure region will exert a force relative to the region of lowered pressure. Pressure reduction may be static, as in a piston and cylinder arrangement, or dynamic, as in the case of a vacuum cleaner when air flow results in a reduced pressure region.

When animals breathe, the diaphragm and muscles around the rib cage cause a change of volume in the lungs. The increased volume of the chest cavity decreases the pressure inside, creating an imbalance with the ambient air pressure, resulting in suction.

See alsoEdit


  1. ^ (LL.D.), Alexander JAMIESON (1827). A Dictionary of Mechanical Science, Arts, Manufactures and Miscellaneous Knowledge.