Human Factors Flashcards
What is haemoglobin?
Iron rich pigment which transports oxygen
What colour cells main function is to carry oxygen around the body?
Red blood cells
What is the vascular system made up of?
Blood vessels forming arteries, capillaries and veins
Being seated for a long time, how can you improve circulation?
Contracting and relaxing your diaphragm as well as elf and buttock muscles
What two respiratory processes occur in the lungs?
Energy giving oxygen breathed in, diffused through thin walls of lungs and into the blood.
Carbon dioxide returned to lungs and breathed out
What two respiratory processes occur in body’s tissues?
Oxygen is brought to body by red blood cells
Carbon dioxide, waste product from burning of carbohydrates carried away in bloodstream
What occurs as we gain height?
Air thins with fewer molecules in the same volume.
Percentage of components remains the same (78 nitrogen, 21 O2, 1other)
Total air pressure falls with altitude as does partial pressure of each of gasses
What is the international standard atmosphere?
Sea level temp 15C Lapse rate -2C per 1000ft Freezing level 7500ft Sea pressure 1013.2 Tropopause 36080 Temp at tropopause -56C
What are the three major effects of altitude on the human body brought about by pressure changes?
Lower external pressure causes gases in body to expand
Lower O2 pressure causes hypoxia
Dissolved gases come out of solution due to decreased external pressure
At what height is atmospheric pressure halved?
18000ft
At what height is oxygen partial pressure halved?
9000 ft
What is hypoxia?
When oxygen concentration in tissues is less than normal
What causes hypoxia?
Lack of O2 in the air
Partial pressure of O2 is too low
Inability of blood to carry O2 due to medical condition or carbon monoxide poisoning
What happens to air pressure and density as altitude increases?
They decrease
What happens to oxygen intake in the lungs with less dense air?
Lower mass of oxygen taken into the lungs with each breath
What are the symptoms of hypoxia?
Euphoria False sense of security Clumsy Difficulty concentrating Moody Drowsy Indecision Giddiness Headache Cyanosis (blue) fingernails and lips Increased pulse rate Increased rate and depth of breathing
Above what height is oxygen required?
10000ft
At what height will night vision start to deteriorate?
4000ft
How long should you wait to fly after donating blood?
24 hours
What are the times of useful activity ?
Alt. Moderate. Minimal 18000ft, 20mins. 30mins 22000ft. 5mins 10mins 25000ft. 2 mins. 3mins 28000ft. 1min. 1.5mins 30000ft. 45s. 1.25mins 35000ft. 30s. 45s 40000ft. 12s. 15s
What is likely to be affected by barotrauma on ascent?
Teeth and intestines
What is likely to be affected by barotrauma on descent?
Ears and sinuses
Blockage of what will cause pressure to be higher on the outside of the ear?
Eustachian tube
When is decompression sickness likely to occur?
When you fly after scuba diving