CAP Flashcards
What are the altitudes for the troposphere?
At Poles: 35,000
At Equator: 65,000
How much does the temperature decrease with elevation in the troposphere?
3.5f (1.98c)/1000 ft.
What layer is above the troposphere?
Tropopause
What is the highest atmosphere strata?
Stratosphere
What is the temperature of the stratosphere?
-55 degrees Celsius
Supplemental oxygen is required when?
Cabin altitude above 12,500 - 14,000, always for min crew above 14,000, ft, and all above 15,000.
In a pressurized aircraft, must have available above 25,000 ft, and must be worn by pilot if alone on flight deck above 25.
When is 100% oxygen required?
Above 35,000 ft.
When is 100% oxygen with positive pressure required?
Above 40,000 ft.
When is a pressure suit required?
Above 50,000 ft.
The stratosphere extends to what altitude
~165,000
What is Armstrong’s line?
63,000 ft, the altitude where water boils at body temperature.
ebullism
Formation of bubbles in human tissue
Dalton’s Law
The total pressure of a gas is equal to the sum of the partial pressure of each gas in the mixture.
Boyle’s Law
Volume of a gas is inversely proportional to its pressure when the temperature is constant.
Henry’s Law
The amount of gas dissolved in solution is directly proportional to the pressure of that gas over the solution.
Graham’s Law
Gas will diffuse from high to low concentration.
Boyle’s Law Equation
P1V1 = P2V2
As you increase altitude, the percent of oxygen ______.
Stays at 21%.
Functional residual volume
Expiratory reserve and residual volume.
Inspiratory capacity
Tidal volume + inspiratory reserve volume.
Vital capactiy
Inspiratory reserve + tidal + expiratory reserve.
TLC
Inspiratory + tidal + expiratory + residual
Review cut off FEV1 and FVC.
70%
Disqualification cut off FEV1 and FVC
50%
Increasing g forces affects lung blood flow how?
Directs blood to the base of lungs and aggravates air trapping.
Alkalosis does what to the oxyhemoglobin dissociation curve?
Shifts the curve to the left (more affinity for O2)
Define hypoxic hypoxia.
Decreased available oxygen due to decreased partial pressure of oxygen.
Histotoxic hypoxia
Interference with tissue oxygen utilization when sufficient oxygen is present.
Define hypemic hypoxia
Reduced oxygen carrying capacity of blood. Think CO, but also anything that shifts the curve to the left.
What are some tricky causes of hypemic hypoxia?
Hemorrhage, anemia, sulpha drugs.
Define stagnant hypoxia.
Reduced blood flow.
1st stage of hypoxia
indifferent, up to 10,000 ft.
2nd stage of hypoxia
Compensatory, 10,000-15,000 ft.
What are the impairments of the compensatory stage of hypoxia?
Decreased efficiency and a 50% decrease in night vision.
What is the third stage of hypoxia?
Disturbance; 15,000 - 20,000 ft. CNS effects may be disabling.
What is the fourth and final stage of hypoxia?
Critical; 20,000-30,000ft. Complete loss of control.
What is the CNS changes at initial increase in altitude?
Vasoconstriction due to decreased CO2 tension secondary to hyperventilation.
What is a post mortem marker for hypoxia in the brain?
Lactic acid.
Alkalosis causes what kind of shift in the hemoglobin curve?
Left shift, more affinity for oxygen.
What is the opthalmologic response to hypoxia.
Reduction of color vision due to decreased oxygen delivery to retinal rods and cones.
What is Time of Useful Consciousness?
The time in which a person can efficiently and effectively perform flying duties in an environment of inadequate oxygen.
First sign of HACE
Ataxia
Medication to treat HAPE?
Nifedipine
Haldane Rule?
When atmospheric pressure reduces by one half, nitrogen bubbles form.
Type I DCS is?
Bends.
Type II DCS is?
CNS, pulmonary, and cardiac manifestations.
Risk factors for DCS
Age, exercise in flight, obesity, alcohol.
Initial treatment of DCS?
100% oxygen. Creates a washout effect. Also, head down slightly; nitrogen bubbles rise to feet. Definitive treatment is compression to roughly 3 atmospheres.
What part of the ear senses horizontal acceleration?
Utricle
What part of the ear senses vertical acceleration
Saccule
What are the otolith organs
Utricle and saccule
What is the black hole takeoff illusion?
Acceleration without visual cues is sensed as a pitching up motion. Can have the flip with deceleration.
What is the inversion illusion
Feeling of falling backwards with abrupt transition from climb to level flight.
Explain the somatogyral illusion.
The semicircular canals cannot accurately detect rotation for prolonged periods. Thus, your body does not feel that it is turning. Beware the steady state turn!
What is the coriolis illusion?
Sense of a roll due to fatigue of the endolymphatic system.
Acceleration is best tolerated in what direction?
Chest to back.
