Flight Physiology Flashcards
What does 1 ATM equal at sea level?
1) 14.71 lbs / sq in
2) 760 mmHg
3) 760 torr
At what altitude does ATM = 0.5?
18,000 MSL
How many feet of water depth equals 1 ATM?
33ft
What is Armstrongs Line?
The pressure of the blood stream is higher than what is in the aviolli causing “off-gasing”.
Boyle’s Law
Boyle’s law is a gas law which states that the pressure exerted by a gas (of a given mass, kept at a constant temperature) is inversely proportional to the volume occupied by it. In other words, the pressure and volume of a gas are inversely proportional to each other as long as the temperature and the quantity of gas are kept constant. Boyle’s law was put forward by the Anglo-Irish chemist Robert Boyle in the year 1662.
Ex: Pneumothorax expands with increase in altitude.
Ex: Air splints or vacuum splints
Dalton’s Law
Dalton’s law states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.
Percentage does not change but number of molecules does with increase in altitude.
Charle’s Law
Charles’s law is an experimental gas law that describes how gases tend to expand when heated. A modern statement of Charles’s law is: When the pressure on a sample of a dry gas is held constant, the Kelvin temperature and the volume will be in direct proportion.
Henry’s Law
Henry’s law is a gas law that states that the amount of dissolved gas in a liquid is directly proportional to its partial pressure above the liquid. The proportionality factor is called Henry’s law constant.
Ex: The Benz
Graham’s Law
Graham’s law states that the rate of diffusion or of effusion of a gas is inversely proportional to the square root of its molecular weight.
What are the four types of Hypoxia?
Hypoxic Hypoxia: In adequate O2 in the alveoli
Hypemic Hypoxia: Inadequate ability to carry O2
Histotoxic Hypoxia: Poisoning or metabolic disorder
Stagnate Hypoxia: Inability to deliver blood to the body
What are the stages of Hypoxia?
1) Indifferent Stage: Tachy, Tachepnic, Loss of night vision
2) Compensatory Stage: Drop in BP and motor skills
3) Disturbance Stage: Dizziness, Sleepiness, ALOC
4) Critical Stage
Equation for FiO2 needed at destination
FiO2i x (BPi/BPf) = FiO2f
FiO2i: FiO2 being administered at origin
BPi: Barometric pressure at origin
BPf: Barometric pressure at destination
FiO2f: FiO2 needed at destination to maintain current PA02
A-a Gradient Equation
PAO2 - PaO2 = A-a
PAO2: Partial Pressure in alveolus
PaO2: Partial Pressure in plasma
A-a diff > 20 = Shunt
Effects of Altitude on pregnant pts
1) More sensitive to hypoxia. Give O2
2) Increased GU expansions will irritate the uterus. Consider NG tube.
3) If flying fixed wing consider gentle flying conditions and feet against G-forces
Is barosinusitis an ascent or descent problem?
Ascent. Slow climb out. Slow descent.
