Everyone knows that our planet is shroudedatmosphere, that is, the shell of air consisting of various gases whose molecules are attracted to the Earth. Thus, the upper layers of air exert pressure on the lower layers, as well as on the surface of the Earth and the objects located on it. Thus, the mass of air causes the normal pressure of the atmosphere.
The history of the discovery of atmospheric pressure takesbeginning in the seventeenth century, when the scientist Torricelli was conducted an experiment using mercury. As a result of this experiment, it was found that the more the height above the Earth increases, the smaller the blood pressure will be. Thus, a formula was developed by which one can calculate the dependence of pressure on the height of the rise above the level of the Earth.
So, the normal pressure of the atmosphere is 760mmHg. However, at the surface of the Earth, atmospheric pressure may vary, depending on location and time. This is especially important in determining weather conditions that are associated with the development of high pressure areas and fast moving air mass with low pressure inside.
Thus, the pressure of the atmosphere ischangeable element, and depends on the height and density of the air column, as well as the force of gravity in a particular place and time interval. But despite the variability, the average monthly value of air pressure on the surface of the Earth is the same every year. The closer to the equator, the lower the blood pressure, so it can be argued that its indicators are affected by the geographical location of the area, time of year and time of day. Thus, the maximum value of atmospheric pressure is observed at ten in the morning and in the evening, while the minimum is at three in the morning and in the afternoon.
It can be said that the atmospheric pressure fluctuates depending on the height above the Earth and the weather conditions, while the normal pressure of the atmosphere is constant.
Blood pressure is measured by special devices calledbarometers, which are similar in structure to the Torricelli device, which made a discovery in science. Normal pressure (mmHg) can also be measured with this instrument. The mercury barometer has the most accurate pressure readings, the only drawback is fragility. Currently, metal barometers or aneroids are widely used.
Atmospheric pressure has the ability to influencehuman body. So, in the case of a decrease in air pressure in humans, there is an increase in respiration and heart rate, as well as a decrease in blood pressure. The basis of the negative effect of blood pressure on a person is oxygen starvation, since a decrease in air pressure contributes to a decrease in oxygen concentration, therefore it enters the human body in smaller quantities, as a result of which anoxemia develops. This phenomenon can be observed in the presence of work related to the ascent to a greater height. However, the normal pressure of the atmosphere in no way affects the state of the human body.
Oxygen starvation causesdizziness, nausea and vomiting, incoordination and rapid fatigability. Moreover, the gases that are in the gastrointestinal tract, stretch the internal organs, and the state of the diaphragm changes, which leads to shortness of breath and impaired functioning of the heart and blood vessels.
High blood pressure can cause headache, painsyndrome in the heart area, an increase in blood pressure, leading to angina or tachycardia. All changes in the human body occur at high speed changes in air pressure.
Thus, normal air pressuremakes one bar. The atmospheric pressure itself is not constant, it changes depending on the time of year and day, on the height above sea level, on the geographical position of the continents and oceans.
