We all know that our planet is enveloped in an atmosphere that is a shell of air, consisting of different gases whose molecules are attracted to the Earth.Thus, the upper air layers exert pressure on the lower layers, and the surface of the earth and the objects disposed on it.Thus, the air mass causes the normal atmospheric pressure.
history of the discovery of atmospheric pressure originates in the seventeenth century, when scientists Torricelli was conducted experiments with mercury.In this experiment it was found that the larger the increasing height above the earth, the lower the blood pressure.So it has developed a formula that can calculate the dependence of the pressure on the lifting height above the ground.
So, the normal atmospheric pressure of 760 mm Hg.However, at the Earth's surface atmospheric pressure may vary, depending on time and place.This is particularly important in determining the weather conditions that are associated with the development of areas of high pressure and fast moving air mass with low pressure inside.
Thus, the pressure of the atmosphere is changeable element, and depends on the height and density of the column of air and gravity in a certain place and time intervals.But despite the volatility, the average monthly value of air pressure at the surface of the Earth the same every year.The closer to the equator, the lower blood pressure, so it can be argued that its performance affects the geographical position of the area, time of year and time of day.So, the maximum value of atmospheric pressure observed at ten o'clock in the morning and evening, while the minimum - at three o'clock in the morning and afternoon.
can say that atmospheric pressure varies depending on the height above the Earth and weather conditions, while the normal pressure of the atmosphere is constant.
blood pressure is measured by special devices, called barometers, which are structurally similar to the device Torricelli, made the discovery in science.Average Pressure (mm Hg) can also be measured using this instrument.Mercury barometer is the most accurate pressure readings, the only drawback it can be considered brittle.Currently, a large widespread metal or aneroid barometers.
atmospheric pressure has the ability to affect the human body.For example, in the case of reducing the air pressure in humans occurs rapid breathing and heart rate, as well as lower blood pressure.The basis of the negative impact on human blood pressure is the oxygen starvation, because the reduced air pressure helps to reduce the concentration of oxygen, so it is ingested in smaller amounts, resulting in growing anoxemia.This phenomenon can be observed in the presence of the work associated with the ascent to high altitude.However, a normal atmospheric pressure does not affect the state of the human body.
Oxygen starvation causes dizziness, nausea and vomiting, incoordination, and fatigue.Furthermore, the gases which are found in the gastrointestinal tract and the internal organs is stretched, and the state of the diaphragm changes, resulting in shortness of breath, and disruption of the heart and blood vessels.
High blood pressure can cause headache, pain in the heart, blood pressure increase, which leads to angina or tachycardia.All changes in the human body occurs at a high rate of change of indicators of air pressure.
Thus, normal air pressure of one bar.The very magnitude of the atmospheric pressure is not constant, it varies depending on the time of day and year, the height above sea level, the geographical location of continents and oceans.
