a colorless, odorless gas that is the life supporting component of the air.

a process in living organisms that produces energy, typically by the intake of oxygen and the release of carbon dioxide.

a pair of organs in the chest that supplies the body with oxygen

any of the minute branches into which a bronchus divides

a dome shaped muscular partition separating the thorax from the abdoman

the airway that leads from the larynx to the bronchi

the tendency toward a relatively stable equilibrium between independent elements