Apnea,
apnoea, or
apnœa (, from ἀ-,
privative, πνέειν, to breathe) is a term for suspension of external
breathing. During apnea, there is no movement of the
muscles of
inhalation and the volume of the
lungs initially remains unchanged. Depending on how blocked the airways are (), there may or may not be a flow of
gas between the lungs and the environment;
gas exchange within the lungs and
cellular respiration is not affected.