Flashcards in The Atmosphere Deck (15):
Review. What percentage of the atmosphere is below 18,000 ft.? What percentage of the atmosphere is oxygen? Nitrogen? Other? What is standard pressure in in. of Hg, Mb, and mm of Hg?
2) 21% oxygen 78% nitrogen 1% other
3) 29.92 inches, 760 mm, 1013.27 mb
What is true altitude?
altitude above standard datum plane
What is cabin altitude?
altitude equivalent pressure being maintained within the cabin. For non-pressurized- close to outside air pressure
What are the properties of gas?
- exerts pressure
- has mass
- is compressible
What is Boyle's Law and what is it's impact?
With a constant temp. volume has an inverse relationship with pressure.
Impact- as you increase altitude- pressure decreases, which means volume increases and gasses need released.
What are some effects of trapped gas when increasing altitude?
1) Barotitis- air trapped in teeth
2) Sinus block- air trapped in sinuses
3) Ear block- gas trapped in middle ear because of Eustachian tube blockage
What are the treatment options for trapped gas related issues involving ascents?
Teeth and Sinus- slow ascent, chew gum, swallow to open Eustachian tubes
What are some remedies for trapped gas problems dealing with descents?
Middle ears- slow descent, valsalva technique- pinch nose force air into ears, yawn and stretch neck
What is Charles' law?
Volume of gas is directly proportional to temp.
What equation derives from the combination of Charles' and Boyle's Law?
What is Dalton's Law?
The total pressure of a mixture of gases is the sum of all partial pressures of gases
What is Henry's Law?
At equilibrium, a gas dissolved in liquid is proportional to the gas pressure.
What is decompression sickness?
Pain and effects from the release of gas out of solution and into the body.
Name and describe the three main types of decompression sickness.
1)The bends- most common (60%). Only symptom is pain. Mild to incapacitating. Remedied by descent.
2) Neurological- bubbles form in central nervous system (5-7%). Mostly brain, sometimes spine. Symptoms- headache, visual disturbance, fatique, emotional outburst (for brain). For spine- paralysis.
3) Creeps- skin and circulatory system. Feels like bugs.