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
nitroglycerin. a chemical well known as an explosive but also having medical uses; it is a vasodilator and is used medically especially in the prophylaxis and treatment of angina pectoris. Called also glyceryl trinitrate.