ABSTRACT
Atmospheric pressure is the weight of the column of air above the aviator and decreases with altitude. With an increase in altitude, the composition of air does not change, but the partial pressure of the components decreases. Gas expands with increasing altitude. Rapid decompression may cause nitrogen to come out of solution in the body, forming bubbles. Gas dysbarisms and barotrauma occur when trapped gases in body spaces expand on ascent. Earth’s atmosphere is a mixture of gases composed of approximately 78% nitrogen, 21% oxygen and 1% other gases: argon, carbon dioxide, water vapor, and so on. Each exerts its own partial pressure. The atmosphere can be broken into three physiological zones: Efficient, Deficient and Space Equivalent. This chapter aims to define the gas laws: Pascal’s law, Boyle’s law, Charles’s law, Graham’s law, Dalton’s law, Amagat’s law and Henry’s law. Change in atmospheric pressure may cause gas dysbarism.
