Title: Physiology of Flight
1Physiology of Flight
2PRE-TEST
3VOCABULARY
- M-1 a maneuver to constrain your vessels and
muscles to keep blood from rushing to your feet
during G-loads
4PRE-TEST
5VOCABULARY
- Physiology the organic processes or functions
in an organism or in any of its parts.
6VOCABULARY
- Hypoxia deficiency in the amount of oxygen
delivered to the body tissues
7VOCABULARY
- Valsalva a maneuver to clear your ears to
equalize pressure
8VOCABULARY
- M-1 a maneuver to constrain your vessels and
muscles to keep blood from rushing to your feet
during G-loads
9Nature of the Atmosphere
- Composition of the atmosphere
- 78 nitrogen, 21 oxygen, 1 carbon dioxide.
- Nitrogen is not used by body to support life.
- Blood and other body fluids contain nitrogen.
- Blood carries oxygen to all parts of the body.
- Oxygen decreases at higher altitudes.
10VOCABULARY
- TUC Time of Useful Consciousness
- 15,000 feet ?
- 22,000 feet ?
- 25,000 feet ?
- 35,000 feet ?
- 45,000 feet ?
11Physiological Divisions of the Atmosphere
12Physiological Divisions of the Atmosphere
Total Space-Equivalent Zone
Pressure
120 miles
Partial Space-Equivalent Zone
No Winged Flight
80,000
Armstrongs Line
63,000
87 mm Hg
50,000
(pressure breathing)
Physiological-Deficient Zone
10,000
583 mm Hg
14.7 psi
760 mm Hg
Sea level
13Nature of the Atmosphere
- Physical Laws of Gases
- Boyles Law
- The volume of a gas is inversely proportional to
its pressure if the temperature remains constant. - Daltons Law
- The total pressure of a mixture of gases is equal
to the sum of the partial pressure of each gas in
that mixture. - Henrys Law
- The amount of a gas in a solution varies directly
with the partial pressure that gas exerts on the
solution.
14Respiration and Circulation
- Respiration is the exchange of oxygen and carbon
dioxide between an organism and its environment. - Closely related to circulation of blood
throughout the body.
15Respiration and Circulation
- Decreasing oxygen pressure places stress on the
body affecting the respiratory system first. - Made up of the lungs, bronchi and their small
branches, windpipe, mouth, and the nose. - Air enters the nasal passages where it is warmed
and moistened and foreign matter removed.
16Respiration and Circulation
17Respiration and Circulation
- The amount of carbon dioxide in the blood has an
important effect on the action of the heart. - As carbon dioxide in the blood increases, the
heart rate speeds up so the heart can send more
oxygenated blood to the tissues. - When carbon dioxide in the blood decreases, the
heart rate slows because tissues need less
oxygen.
18Respiration and Circulation
- The respiratory system acts to keep the amount of
oxygen in the body tissues constant.
19Effects of Reduced Pressure at Altitude
- As the body goes to high altitude it must make
adjustments to the reduced atmospheric pressure
in order to keep the body tissue constant. If
the pressure outside the body is greatly reduced
and the body is not adequately protected, it
cannot make the necessary adjustments.
20Effects of Reduced Pressure at Altitude
- Hypoxia - a deficiency of oxygen in the body
cells or tissue. - Most frequently the result of decreased pressure
on an unprotected body. - In flight is usually caused by an insufficient
amount of oxygen in the inhaled air. - Greatest danger when pilot becomes engrossed in
duties and doesnt notice the first symptoms.
21Normal Body Function Breathing
- For normal breathing, your body will breathe in
the air around it. - This air contains 21 oxygen, 78 nitrogen, and
other trace elements. - Normally, your blood has a concentration of 75
of oxygen. - Your lungs will add more oxygen to it, so when
the blood reaches your brain, it has 98
saturation of oxygen.
22Pilots are at the greatest risk!
- The air maintains the same concentration of
elements at any height. - The reason you have difficulty breathing at
higher altitudes is the drop in atmospheric
pressure. - Your lungs are unable to draw in enough air to
maintain the oxygen levels that you need.
23Ready For Takeoff!
At takeoff, your body is pulling 21 oxygenated
air into your lungs to change the 75 of the
oxygen saturated in your blood to 98 saturation
for your brain.
24Going UP!
But, air pressure is 25 less
The lower oxygen levels to your body begins to
affect your night vision and your ability to
handle new tasks.
When the altitude increases to 8,000 feet, your
body still pulls 21 oxygenated air into your
lungs. But, your blood has 65 oxygen
saturation that becomes 95 saturated for your
brain.
25Still going UP!
But, air pressure is 45 less
The lower oxygen levels to your body reduces your
physical capacity and impairs skilled task
performance.
When the altitude increases to 15,000 feet, your
body still pulls 21 oxygenated air into your
lungs. But, your blood has 55 oxygen
saturation that becomes 80 saturated for your
brain.
26Still going UP!
But, air pressure is 65 less
The lower oxygen levels to your body shows
obvious physical and mental impairment, and can
lead to unconsciousness.
When the altitude increases to 25,000 feet, your
body still pulls 21 oxygenated air into your
lungs. But, your blood has 35 oxygen
saturation that becomes 60 saturated for your
brain.
27Coming back DOWN!
But, air pressure is 75 less
The lower oxygen levels to your body rends you
incoherent in seconds and causes a complete loss
of consciousness.
When the altitude increases to 35,000 feet, your
body still pulls 21 oxygenated air into your
lungs. But, your blood has 25 oxygen
saturation that becomes 50 saturated for your
brain.
28Flying Right At Any Height!
With the altitude at 35,000 feet, the air
pressure is still 75 less than at sea level.
However, added oxygen through a mask can
supplement what the lungs are unable to breathe
in.
29Effects of Reduced Pressure at Altitude
- Hyperventilation
- A person affected by hypoxia tends to increase
breathing rate in an attempt to take in more
oxygen. - May result from great emotional tension or
anxiety.
30Effects of Reduced Pressure at Altitude
31Effects of Reduced Pressure at Altitude
- Trapped Gases-Sinus Block
32Effects of Reduced Pressure at Altitude
- Trapped Gases-Tooth Pain
- Untreated cavities where pulp is exposed may be
the cause of tooth pain at altitude. - The toothache often disappears at the same
altitude that if was first observed on ascent. - Gases may be trapped in the teeth at altitude in
abscesses.
33Effects of Reduced Pressure at Altitude
- Trapped Gases-Stomach and Intestines
- In flights above 25,000 feet the expanding gases
may cause severe pain, lowering blood pressure
and eventually shock. - Usually air that has been swallowed.
- When barometric pressure falls the partial
pressures of the gases in the body fluids
decrease. - The escaping gases cause decompression sickness.
34Effects of Reduced Pressure at Altitude
- The Bends
- Release of nitrogen into
- the joints of the body.
35Effects of Reduced Pressure at Altitude
- The Chokes
- Another form of decompression sickness.
- Deep, sharp pains under the sternum.
- Increased expansion of the lungs causes the pain
to increase.
36Effects of Reduced Pressure at Altitude
- Skin Symptoms
- Type of decompression sickness that involves
sensations of the skin. - Small bubbles of nitrogen under the skin produce
itching, hot and cold feelings and tingling. - The rash does not disappear with descent and may
last for hours.
37Effects of Reduced Pressure at Altitude
- Treatment of Decompression Sickness
- As decompression sickness becomes more severe,
the pain caused by escaping gas bubbles becomes
more intense. - As symptoms appear in flight, 100 oxygen should
be administered. - If symptoms still exist after landing,
compression therapy will be administered at the
nearest hyperbaric facility.
38Rapid Decompression
- Rapid decompression at a high altitude brings on
an explosion as the pressure suddenly decreases. - At 63,000 feet or above body fluids boil if
exposed to the ambient atmosphere. - The time of useful consciousness may be reduced
by 60 if the decompression is rapid and the air
is forced out of the lungs due to rapid expansion.
39Principles and Problems of Vision
40(No Transcript)
41Principles and Problems of Vision
Color Blind Test
42Principles and Problems of Vision
Aspen at Night
43Spatial Disorientation and Motion Sickness
- Spatial disorientation - the inability to
accurately orient yourself with respect to the
Earths horizon. - We use four sensory systems to maintain our
orientation and equilibrium (balance).
44Spatial Disorientation and Motion Sickness
- The Visual System
- Eyes provide the strongest and most reliable
orientation information during flight. - When the horizon is not correct, your vestibular
disorientation disappears you may still
experience visual illusions caused by false
horizon.
45Spatial Disorientation and Motion Sickness
46Spatial Disorientation and Motion Sickness
47Spatial Disorientation and Motion Sickness
- The Somatosensory System
- Consists of tactile pressure receptors in the
skin, muscles, tendons and joints. - Often called the seat-of-the-pants sense.
48Acceleration and Deceleration Increased G-Forces
- When military flight crews perform maneuvers or
when astronauts are launched or recovered they
may be subjected to severe stress from the
effects of acceleration and deceleration. - The stresses are felt as increases in weight or
gravity forces (G-Forces).
49Acceleration and Deceleration Increased G-Forces
50Noise and Vibration
- Cause flyers more inconvenience than any other
factor in flight. - Sound intensity or loudness is measured in
decibels. - Vibrations are measured in frequency.
- One effect of vibration is blurred vision.
51Heat and Cold During Flight
- The largest amount of heat is generated on the
skin of aircraft and spacecraft as it travels at
high speeds through the atmosphere. - An aircraft flying at Mach 2 has skin
temperatures increased by about 400o F as a
result of aerodynamic heating. - There are two dangers associated with exposure of
the body to cold.
52Noxious Gases and Vapors
- Inside an enclosed cabin, noxious gases and
vapors may accumulate. - The breathing atmosphere can easily become
contaminated from inside sources if care is not
taken. - Carbon Monoxide.
53Self-Imposed Stresses
- Alcohol
- One drink at 10,000 feet can have the same effect
as two or three drinks at sea level. - Tobacco
- Smoking at 10,000 feet produces effects
equivalent to those experienced at 14,000 feet
without smoking. - Drugs
- Aspirin, nasal decongestants, tranquilizers or
sedatives.
54Summary
- 1. Nature of the Atmosphere
- 2. Respiration and Circulation
- 3. Effects of Reduced Pressure at Altitude
- 4. Rapid Decompression
- 5. Principles and Problems of Vision
- 6. Spatial Disorientation and Motion Sickness
55Summary
- 7. Acceleration and Deceleration Increased
- G-Forces
- 8. Noise and Vibration
- 9. Heat and Cold During Flight
- 10. Noxious Gases and Vapors
- 11. Self-Imposed Stresses