BPK 306 Lecture Notes - Lung Volumes, Breathing Gas, Respiratory Tract
1 Dec 2011
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Document Summary
The first air expired is the last air in which is pure o2 w/ no nitrogen: nitrogen conc"n begins to rise thereafter, reflecting beginning of expiration of alveolar gas. Doesn"t rise instantaneously b/c of some mixing of gas betw. dead space volume and alveolar volume at the interface as well as some anatomical anomalies: can determine dead space from nitrogen expiration trace. Can determine from volume of air corresponding to the hatched area: alveolar volume va= ve vd, rates, maximal breathing capacity (mbc, measurement actually a rate aka maximal voluntary ventilation (mvv, subject connected to respirometer. Ventilates as much air as possible in 12 sec (l/min: method not very useful b/c optimal combination of breathing frequency and tidal volume is not achieved, cannot measure up to a vo2 max test. Can discriminate betw. obstructive and restrictive lung disease: when expiratory flow rate is graphed against lung volume from.
