lung volumes

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lung volumes

Physiology A group of air 'compartments' into which the lung may be functionally divided
Lung volumes  
Expiratory reserve capacity–ERV The maximum volume of air that can be voluntarily exhaled
Functional residual capacity (FRV) Volume left in the lungs at the end of a normal breath which is not normally part of the subdivisions
Inspiratory capacity–IC The maximum volume that can be inhaled
Inspiratory Reserve capacity–IRC The maximum volume that can be inhaled above the tidal volume
Tidal volume–VT The normal to-and-fro respiratory exchange of 500 cc; vital capacity is the maximum amount of exhalable air; after a full inspiration, which added to the residual volume, is the total lung capacity
Total lung capacity–TLC The entire volume of the lung, circa 5 liters
Vital capacity–VC The maximum volume that can be inhaled and exhaled  
Lung volumes.

lung volumes

measurements made as part of pulmonary function tests; the volumes that move in and out during the normal breathing cycle, and with deliberate additional effort, can be measured directly by spirometry with the subject breathing through a closed circuit in and out of a cylinder inverted over water, or into a vitalograph, or by pneumotachograph; the residual volume can be measured only indirectly by dilution methods (usually with helium) or by whole body plethysmography. See also ventilation. See figure and table overleaf .
Table 1: Lung volumes
VT (TV)Tidal volumeVolume of inspired/expired air moving in and out with each breath
IRV
ERV
Inspiratory and expiratory reserve volumesUsed when tidal volume increases above that at rest
VCVital capacityVolume that can be inspired/expired after full expiration/inspiration
FEV1Forced expiratory volume in 1sVolume exhaled in the first second, with maximal effort after full inspiration
FRCFunctional residual capacityVolume remaining in the lungs at end-expiration; decreases as tidal volume increases
RVResidual volumeRemains after a maximal expiratory effort; cannot be exhaled
TLCTotal lung capacityVital capacity + residual volume
References in periodicals archive ?
14,38) Helium dilution and nitrogen washing can also be used to measure functional residual capacity in patients with COPD, (14) but body plethysmography is considered to be a more accurate method of lung volume evaluation in patients with severe airflow obstruction.
In order to detect the presence of air trapping in the lungs, lung volumes should be measured to determine the total lung capacity and the residual volume.
Lung volumes were estimated by water displacement, as previously described (Scherle 1970).
However, the consistent trend of decrement in lung volumes is important and provides basis for further research.
A reduction of lung volumes in smaller airways was demonstrated in these patients.
Research is beginning to suggest that lung volume may play a more significant role in upper airway patency than previously thought.
Altered IAP may influence the lung volume, the degree of caudal tracheal traction exerted on the UA and consequently the UA collapsibility.
It carries much less risk and complication and requires a far shorter hospital stay than surgical lung volume reduction.
Among these are the forced expiratory volume achieved during the first second of maximal expiration (FEVi), and the expiratory flow rate occurring when the lung volume is at various percentages of VC (e.
I think the evidence is that breastfeeding increases lung volume irrespective of whether the mother is asthmatic or not.