Investigation was carried out with use of the automated microprocessor a method of registration of parameters curve "stream - volume" of the forced exhalation. For an estimation of a condition of function of external breath studied the following parameters: frequency of breath 1 minute, vital volume of lungs (VVL), minute volume of breath (MVB), respiratory volume (RV), volume of the forced exhalation for 1 secund (VFE), the maximal volumetric speed at a level of 75%, 50%, 25% and 25-75% forced VVL, peak volumetric speeds of an exhalation and breath (ÏÎÑ), test Tiffno attitude forced VVL for 1 s to VVL (%), resistance of respiratory ways.
Absolute values of volume-speed parameters increase with the years. Relative sizes did not depend on age and were above the bottom border of physiological norm. So VVL were within the limits of 90-107%. Parameters of bronchial passableness at a level 75, 50, 25% FVVL laid from 96 up to 131%. With the years the increase on the average on 200-510 sm3 at boys is marked (higher than at girls). So, at girls of 9 years VVL it is equal 1950 sm3, and 15 years - 3650 sm3, at boys – 2320 and 4190 sm3 accordingly (Ð<0,01). The minute volume of breath is a little higher at boys. It is connected apparently to the a little bit greater physical activity of boys. We investigated the parameters describing a condition of bronchial passableness. Statistical distinctions of these sizes are marked in the subgroups 12-15 years. The average sizes describing a condition of bronchial tubes which did not fall outside the limits the bottom border of physiological norm (<85% to due) testify to it. At 40 % of smoking teenagers decrease in one and more parameters curve stream - volume FVVL is revealed. Among non-smokers - at 12,8 %, ò.å in 3 times less often. The received facts confirm negative influence of smoking on respiratory function.