Exhalation - Exhalation & Gas Exchange

Exhalation & Gas Exchange

The main reason for exhalation is to rid the body of carbon dioxide, which is the waste product of gas exchange in humans. Air is brought in the body through inhalation. During this process air is taken in through the lungs. Diffusion in the alveoli allows for the exchange of O₂ into the pulmonary capillaries and the removal of CO₂ and other gases from the pulmonary capillaries to be exhaled. In order for the lungs to expel air the diaphragm relaxes, which pushes up on the lungs. The air then flows through the trachea then through the larynx and pharynx to the nasal cavity and oral cavity where it is expelled out of the body. Exhalation takes longer than inhalation since it is believed to facilitate better exchange of gases. Parts of the nervous system help to regulate respiration in humans. The exhaled air isn’t just carbon dioxide; it contains a mixture of other gases. Human breath contains volatile organic compounds (VOCs). These compounds consist of methanol, isoprene, acetone, ethanol and other alcohols. The exhaled mixture also contains ketones, water and other hydrocarbons.

It is during exhalation that the olfaction contribution to flavor occurs in contrast to that of ordinary smell which occurs during the inhalation phase.