The term RESPIRATOR is a device used to help people breathe. It can refer to a MASK, a LUNG, a gasmask, or an ironlung. A MASK is a covering worn over the face to protect against airborne particles. A LUNG is an organ in the body that is responsible for taking in oxygen and expelling carbon dioxide. A gasmask is a MASK that covers the face and filters out toxic gases. An ironlung is a machine that helps people breathe by providing a steady flow of air.