Atmospheric air is a mechanical mixture of several gases. Most
Part of this mixture is nitrogen (78, 13% by volume), then - oxygen (20, 90%). In addition to these two gases in the atmosphere contains, albeit in small amounts, carbon dioxide (0.03%) and argon (0.94%) and traces of hydrogen and various inert gases (helium, neon, krypton, xenon).
Nitrogen in normal conditions is like a neutral body for gas. Once in the human lungs during respiration, it shall not enter into chemical combination with the blood and excreted from the body through the lungs.
Oxygen is the most important person for part of the air. In humans, the oxygen enters in connection with a particular substance - the hemoglobin inside the red blood cells. These corpuscles oxygen carried by blood to all body tissues, where the exchange of gases between the blood and tissues. The blood gives oxygen to tissues, going to the oxidation or "burning" of nutrients and takes away from the tissues resulting in them carbon dioxide. Human life is impossible without oxygen, so a sudden interruption in the supply of oxygen or even a decrease in oxygen delivery to tissues (especially the brain) can result in serious condition, called anoxia, and the death of the organism. This disease can occur if the oxygen concentration in the inhaled air will be less than 16% at normal pressure (changes in the oxygen content in the air for 1-2% of people almost do not feel).
Carbon dioxide content with a slight increase in the inspired air (1%) does not adversely affect the human body. However, the high content of carbon dioxide in the air can come poisoning.
Other gases that make up the air, present it in such small quantities that have no effect on the human body do not have.
Speaking of air, we should mention one more integral part of it - namely, of water vapor, whose number can range from one percent to 4% by volume. The higher the temperature, the more water vapor it can contain. Amount of water vapor in the air do not care for human beings. When humidity is high a person can come violation of the normal processes of emission and absorption of heat. |
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