Lung volumes
The physiology of respiration is characterized by different volumes (including respiratory gas volumes, tidal volumes, lung volumes ) of the air in the lungs and airways.
Breathing air (including tidal volume ) denotes the per breath exhaled and inhaled ( ventilated ) amount of 0.5 liters during tidal breathing.
The tidal volume can be extended by a further 3 liters of willful valving, which represents the lung available for the reserve volume (including make-up air, reserve air). The 1.5 liter is accounted for by inspiratory and expiratory reserve volume. Taken together, breathing air and supplementary air a supply of 3.5 liters, the man can ventilate in one breath. This amount refers to the vital capacity. After maximum expiration remain 1.5 liters of air as residual volume in airways and lungs. Taken together, vital capacity and residual volume yield the total capacity.
The respiratory period volume is the volume of air which is inhaled and exhaled in a certain period of time. It is measured in l / min and defined as respiratory rate multiplied by tidal volume. At rest, it is about 7.5 l / min. Respiratory limit ( also minutes limit ) is the maximum at the maximum tidal volume and respiratory rate per minute ventilierbare air volume. Respiratory limit is usually 120 to 170 liters per minute.
The functional residual volume refers to the volume of air remaining in the lungs during normal breathing (the sum of reserve volume and residual volume ).
Figures are the averages in adult humans. Some people have up to six liters of vital capacity. Around the age of 20 years, the man reached the maximum vital capacity V. It is 3 to 4 liters and can drop the age to values of less than 2 liters. Competitive swimmers reach values of 8 liters, freediver Herbert Nitsch world record holder as the even up to 10 liters.
As a guideline, for an adult young man, depending on his size G, valid for V in liters:
In women, this value is smaller by about 25%:
Most lung volumes can be determined using a spirometer. To determine the residual volume and total lung capacity, however, a Bodyplethysmograph is needed.