respiration

A physiological term with a range of related meanings: (1) the act of breathing, whereby terrestrial animals move air in and out of their lungs, and aquatic animals pump water through their gills; (2) the uptake of oxygen from and the release of carbon dioxide to the environment; and (3) the metabolic processes by which organisms derive energy from foodstuffs by utilizing oxygen (aerobic respiration) or without the involvement of oxygen (anaerobic respiration); often referred to as tissue or cell respiration. In humans, breathing is achieved by periodic changes in the volume of the thoracic cage (produced principally by the contraction of the diaphragm and the movement of the ribs) which draws air into the lungs (inhalation) or expels air from them (exhalation). Oxygen diffuses from the alveoli into the pulmonary capillaries, and is carried to the tissues for use in aerobic respiration. Carbon dioxide (the main end product of aerobic respiration) is carried by blood to the lungs for release into the environment.

Respiration is a term used in both organismal biology and biochemistry, and may refer to:

Respiration, the process by which an organism obtains energy by reacting oxygen with glucose to give water, carbon dioxide and energy. Cellular respiration, the process in which the chemical bonds of energy-rich molecules such as glucose are converted into energy usable for life processes. Anaerobic respiration, a process that allows respiration without use of oxygen. If an internal link led you here, you may wish to change the link to point directly to the intended article.