ventilation

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ventilation in the physiological sense (strictly, pulmonary ventilation) refers to the volume of air breathed in and out of the lungs: typically 5–6 litres per minute for an average-sized person at rest, with the possibility of increasing by up to twenty-fold in exercise. For example, the size of each breath (tidal volume) could vary from 0.5 to 3 litres, and the number of breaths per minute from 10 to 40. When for any reason breathing stops or becomes inadequate, or if natural breathing is prevented by drug-induced muscle relaxation as an adjunct to anaesthesia, mechanical or artificial ventilation (also known as artificial respiration) is necessary. Methods range from mouth-to-mouth breathing to machines which pump gas rhythmically into the lungs

Stuart Judge


See breathing; breathing during exercise.

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