Involved in the mechanics of breathing; The muscles involved in this type of breathing are the diaphragm, the external intercostal muscles, and the accessory respiratory muscles (activated when respiration increases significantly) Forced Exhalation.
Nitro- a combining form (used also adjectively) designating certain compounds of nitrogen or of its acids, as nitrohydrochloric, nitrocalcite; also, designating the group or radical NO2, or its compounds, as nitrobenzene
combining form. 1  indicating that a chemical compound contains a nitro group, -NO2: nitrobenzene. 2  indicating that a chemical compound is a nitrate ester: nitrocellulose.