Aerospace Physiology JP101-JP112 Flashcards
Human factors - JP101
study of the physiological, physical, psychological, and pathological limitations and capabilities of people as they interact with their environment
atmosphere
the gaseous envelope surrounding the Earth
Atmospheric Functions
It contains oxygen, essential for animal life and carbon dioxide, essential for plant life. It is a shield that attenuates cosmic and ultraviolet radiation.
Precipitation occurs in the atmosphere, helping maintain the temperature and climate.
Atmospheric Composition
The gaseous envelope surrounding the Earth contains nitrogen, oxygen and argon with traces of carbon dioxide and inert gases (such as helium and neon).
Atmospheric Gas Percentages
The approximate percentages of gases in the atmosphere are 78 percent nitrogen, 21 percent oxygen and 1 percent other gases (including 0.03 percent carbon dioxide).
Pressure
Force/Area
Units of measurement for pressure
psi, mmHg, inHg
Atmospheric or barometric pressure
the combined weight of all the atmospheric gases acting to create a force upon the surface of the Earth.
standard temperature lapse rate
altitudes up to about 35,000 feet reflect a constant decrease in temperature of about 2 deg C (3.6 deg F) per 1,000 feet
physiological zone
extends from sea level to approximately 10,000 feet and is the zone the human body is adapted to
altitude when the use of supplemental oxygen is required
When flying unpressurized above 10,000 feet MSL
Physiological Deficient Zone
This zone extends from approximately 10,000 feet to approximately 50,000 feet. Because of reduced atmospheric pressure, inadequate oxygen is available to sustain normal physiologic functions. Also, decompression sickness (caused by evolved gas) can occur in the body tissues and joints.
Altitude required for pressure suits
FL500
Space Equivalent Zone
exists above 50,000 feet. The physiological problems of flight above 50,000 feet are essentially the same as those for space. The need for protection in a sealed cabin or pressure suit, the problem of ebullism (tissue water vaporization) above 63,000 feet
mmHg in each zone
760 at 0 MSL, 523 at 10,000 MSL, 87 at 50,000 MSL
Partial Pressure
the amount of pressure that a single gas out of a mixture of gases contributes to the sum or total pressure of that mixture, designated with a P in front of the element/compound symbol
Dalton’s Law
explains how exposure to a high ambient altitude can reduce the available oxygen. As ambient altitude increases, the partial pressure of oxygen (PO2) decreases even though the percentage of oxygen remains the same.
Boyle’s Law
When the temperature remains constant, as in the human body, a volume of gas is inversely proportional to the pressure surrounding it.
Henry’s Law
the amount of gas in a solution varies directly with the partial pressure of that gas over the solution.
The Law of Gaseous Diffusion
A gas will diffuse from an area of higher concentration or pressure to an area of lower concentration or pressure until equilibrium is reached.
Charles’ Law
When volume is constant, the pressure of a gas increases or decreases proportionally to an increase or decrease in its temperature.
Respiration - JP102
the process our body uses to exchange gases with our environment. The primary purpose of respiration is to provide oxygen to, and remove excess carbon dioxide from, the body. The respiratory process also helps maintain the acid-base balance (pH) of the blood.
Metabolism
the sum of all the physical and chemical processes used by cells to produce energy and building materials needed to sustain life.
Phases of Respiration
ventilation, diffusion, transportation and utilization