Flight Physiology Flashcards
The pressure of a gas is inversely proportional to the volume of a gas at a constant temperature.
Boyle’s Law
Boyle’s Law
The pressure of a gas is inversely proportional to the volume of a gas at a constant temperature.
Boyle’s formula
P1V1 = P2V2
Boyle’s Law affects:
ETT cuffs (9x the volume)
MAST trousers
air splints
IV drip rates (air in bag expands and increases rate)
If pneumocephalus present, intracranial pressure will
increase
Dalton’s Law
The total pressure of a gas mixture is the sum of the partial pressures of all the gases in the mixture.
The total pressure of a gas mixture is the sum of the partial pressures of all the gases in the mixture.
Dalton’s Law
Law of Partial Pressures (additive gas law)
Dalton’s Law
This law is responsible for soft tissue swelling at altitude (uptake of inert gases into tissue).
Dalton’s Law
Pt = P1+P2+P3+P4…+Pn
Charles’ Law
At a constant pressure, the volume of gas is directly proportional to the absolute temperature of the gas.
At a constant pressure, the volume of gas is directly proportional to the absolute temperature of the gas.
Charles’ Law
This law has very little effect on the human body
Charles’ Law
Gay-Lussac’s Law
Directly proportional relationship between temperature and pressure.
Directly proportional relationship between temperature and pressure.
Gay-Lussac’s Law
Gay-Lussac’s Law formula
P1/T1 = P2/T2
Charles’ Law formula
V1/T1 = V2/T2
Gay-Lussac’s example:
add air to tires in winter (colder temps, lower pressure)
Graham’s Law
Law of gaseous diffusion
Law of gaseous diffusion
Graham’s Law
Gas exchange at the cellular level
Graham’s Law
The rate of diffusion of a gas through a liquid medium is directly related to the solubility of the gas and inversely proportional to the square root of its density
Graham’s Law
Graham’s Law
The rate of diffusion of a gas through a liquid medium is directly related to the solubility of the gas and inversely proportional to the square root of its density
Graham’s Law limits the ability of gas to move through
liquid
Henry’s Law
Solubility of gas in liquid
Solubility of gas in liquid
Henry’s Law
Henry’s Law
The quantity of gas dissolved in 1 cm3 (1mL) of a liquid is proportional to the partial pressure of the gas in contact with the liquid.
The quantity of gas dissolved in 1 cm3 (1mL) of a liquid is proportional to the partial pressure of the gas in contact with the liquid.
Henry’s Law
Law associated with decompression sickness
Henry’s Law
Affects divers, can lead to decompression sickness (“the bends”).
Henry’s Law
The most common form of decompression sickness:
The Bends
Boyle’s Pneumonic
Balloon
Barotrauma
Boyle’s example(s):
Air filled medical device expansion
Pneumocephalus
AGE
Dalton’s Pneumonic
Dalton’s Gang
Dalton’s example(s):
Soft tissue swelling at altitude
Charles’ Pneumonic
Charging Charles
Charles’ example(s):
oxygen tank getting hot when filled
Graham’s Pneumonic
Grey matter
Graham’s example(s):
gas bubbles from exposed grey matter
Henry’s Pneumonic
Heineken
Henry’s example(s):
decompression sickness (the bends)
Decompression sickness such as the “Bends” is related to which law
Henry’s Law
How many types of decompression sickness are there?
6
Type I Decompression Sickness signs/symptoms:
nitrogen related painful joints, mottled skin, pruritic itching
Patient may have this sensation in Type I Decompression Sickness:
ants crawling on skin
Cutis marmorata
mottle skin associated with Type I decompression sickness; can look like a sunburn
Type II Decompression Sickness signs/symptoms:
neurologic s/s
hypovolemic shock
In all diving injuries/decompression sickness, this type of transport is preferred:
Ground
Arterial Gas Embolism (AGE) is related to which law?
Boyle’s (barotrauma)
(AGE) Breath holding during ascent on a dive, air pushes through the alveoli and enters the skin in the neck/chest causing a:
Pneumothorax
(AGE) Air is forced into blood vessels; bubbles block blood vessels, causing:
ischemia
(AGE) Patient presents with stroke-like symptoms (AMS, syncope, dizziness) and may also have a:
cough and epistaxis
AGE requires immediate:
hyperbaric treatment
Patients with AGE must fly in a
pressurized aircraft (fixed wing) or rotary wing <1000ft MSL
Pulmonary overpressurization (POP) is related to which law?
Boyle’s Law
The greatest pressure differences are just below the surface of the water:
= 4 foot depth
(POP) A syndrome that occurs when “breath holding” compressed air during ascent causes:
lung over-expansion
ruptures alveoli
pneumothorax
mediastinal emphysema
(POP) is common in
inexperienced divers
(Atmosphere calculations)
Every 33 feet below water is:
1 atmosphere
(Atmosphere calculations)
Sea level =
1 ATM
(Atmosphere calculation)
33 feet under water =
2 ATM
(Atmosphere calculation)
66 feet under water =
3 ATM
ATM may also be written as
atmospheres absolute, or ATA
Diver’s Alert Network (DAN)
24 hour hotline for diving related injuries and questions
DAN network website
www.diversalertnetwork.org
DAN hotline
(919) 684-9111
AGL
above ground level
ASL
above sea level
MSL
mean sea level
ASL and MSL are
equivalent
