Effects of altitude Flashcards
Pressure at sea level, 18000 ft and 34000 ft
760 mm Hg sea level
1/2 at 18,000 ft
1/4 at 34,000 ft
Temperature drop with altitude
Temp drops about 2 degrees per 1000 ft
Outline traped gases
When ever drop in pressure, any trapped gas will tend to expand. Creates pressure differential across wall of what ever is trappig it.
Stomach, intestines, behind ear drum, middle ear, sinuses.
Eustachian tube
The Eustachian tube is an opening that connects the middle ear with the nasal-sinus cavity
Outline trapped gas pain on decent
Trapped gas will tend to want to created a vacume, pain can arrise in sinuses and ears. Made worse when eustachian tube blocked during illness
Atmosphere composition
80% nitrogen. 20% oxygen.
Oxygen partial pressures
Sea level 150 mm Hg
102 mm Hg in lungs.
Most sensistiev organs from oxygen point of view
Brain, and visual system
Anemia
Reduced red blood cell (hence haemoglobin) count. Can result from low iron diet or recent blood donation.
Hypoxia
Condition of insufficient oxygen to function properly
Hypoxia symptoms
Fuzziness, thick feeling in the head. Slowness of thought. Poor judgement and memory. Unatural feeling of being unwell (euphoria). Mental fixiation on unimportant tasks. Loss of visual sharpness, dimming, tunnle vision, reduced colour vision. Deep, faster breathes.
Times of usefull conciousness
15-30 minutes at 18,000 ft.
3-5 minutes at 25,000 ft.
45-60 seconds at 35,000 ft.
Outline the bends
Decreases pressure on assent results in niutrogen comming out of soloution and forming gas bubbles. Bubbles can become lodged in joinst, brain, spinal cord, uner skin.
Can cause paraplegia (permanent paralysis/loss of use of limbs), itchiness, numbess, tingling, problems with coordination and movement.
