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
Nitric oxide is a chemical compound that has a chemical formula of NO, meaning that it consists of one nitrogen atom and one oxygen atom. It's classified as a free radical (which is a group of atoms with unpaired electrons) because it has an unpaired electron present on the nitrogen atom.