What is a simple definition of FEV1?
The Forced Expiratory Volume of air in breathing is a measurement of air that is forcibly expelled from the lungs in an exhalation (this is different from a resting exhalation, which uses the natural relaxation of the lungs and surrounding muscles). FEV1 is the measurement of air forcibly expelled from the lungs in the first second of an exhalation; this is measured after a full-volume inhalation, and measures the strength of the lungs both in volume and in force of exhalation. These tests are commonly performed on patients with lung-related illnesses or conditions such as asthma, which can impair lung volume and strength. These measurements are collected into a practice called Spirometry (a sub-field of Pulmonary Function Tests), and are vital in the diagnosis and treatment of conditions that impair lung function.
The alveolar ventilation rate is the amount of new atmospheric air that gets into the alveoli. Alveoli are microscopic air bags in your lungs where the exchange of oxygen and carbon dioxide occurs.
FEV 1.0 is the volume of air exhaled forcibly in the first second after maximal inhalation. FEV 1.0 is the measure of the expiratory power of your lungs.