Lecture 2- Physiology and Effects of Flight

7/30/2019 Lecture 2- Physiology and Effects of Flight

1/99

1

Human Physiology & Effects of

Flight


2/99


3/99


4/99


5/99

understanding how the body and mind can beaffected in flight as well as why they are affectedin flight.

clear understanding and overview of the many andvaried physiological situations that can interferewith safe flight.

prevent impairment and reduce the risk of a

human factorsrelated incident or accident. being knowledgeable about the physiology of the

body in the flight environment further increasessafety.


6/99

Human Factors and Flight Safety

Why Important?

Flight physiology and human factors both

have an impact on flight.

More than 70 percent of aviation accidents

and incidents are in some way related to

human factors.


7/99

Accident vs. Incident

An accident is one incident too many.

No accident occurs without a series ofincidents happeningbeforehand.

Its a chain of events that will eventually end up as anaccident unless someone breaks that chain.

Contributing factor to an accident is probably associatedwith an incident of varying significance that could have

been averted and the accident prevented. Always look for the contributing factors, because those

usually can be controlled. The final event and the resultingaccident cannot be reversed.


8/99

Flight physiology is the most important part of

human factors. Its the human element of human

factors and safe flight, and it has a direct effect onperformance.

Knowing flight physiology, being aware of its

effects on performance, and maintaining a high

index of suspicion when performance becomessubstandard will continue to make everyone a

better and safer pilot.


9/99

Human Factors & Flight Physilogy

the effects of fatigue, hypoglycemia, illness, noise, andother medical and psychological issues.

Flight physiology is how the body and mind work in the

flying environment. It includes such topics as understanding how our organs

function, what keeps them from functioning in a hostileenvironment, and what the pilot can do to protect thesefunctions before and during flight.

It is essential to safe flight.

Flight physiology, therefore, is an integral part of humanfactors and safe flight.


10/99

H

LS E

L

FRAMEWORK OF HUMAN FACTORS


11/99

S - Software (procedures, documentation, symbology,etc.)

H Hardware

(technology, machine, equipment)

E - Environment

(weather, temperature, noise)

L - Liveware (human)(people, leader, follower, human element

L I V E W A R E

Core of the model comprised ofhuman operators, mostflexible and critical component in the system.

S H E L L


12/99

The model is also important in explaining why the

physiology of flight is important, since the human

element is obviously crucial and central and everyaspect of physiology will affect every other

interaction as defined in the model.

Human factors are how these interfaces and

interactions ultimately affect performance; humanfactors are a dynamic process.


13/99

Flight Physiology Objectives

prevention of incapacitation or

impairment, whether physical or mental.


14/99

Incapacitation & Impairment

Incapacitation is defined as being incapable of performingexpected normal activity.

Mental incapacitation is the minds inability to use proper

judgment, reasoning, and decision making. Beyond that, mental incapacitation turns into

neurological incapacitation, whereby the signals fromthe brain fail to use the sensory information and data fromthe eyes, ears, touch, smell, and the like.

Physical incapacitation refers to the bodys inability tofunction in an expected way. The end result in any of theseincapacitating or impairing situations is an unsafe andpoorly performing pilot.


15/99

HUMAN ANATOMY


16/99

ELO #3

Identify the components of the circulatory

system that transport oxygen throughout the

human body.


17/99

how the body should work under ideal and

controllable situations, and raise the level of

awareness of what can, and often does,happen in less than ideal conditions.

brain, musculoskeletal, gastrointestinal,

metabolic, and circulatory.


18/99

What is Physiology?

The study of human systems' integrated

functions and the processes by which theymaintain the body functions.


19/99

What is Human Physiology?

Human physiology is the science of themechanical, physical, and biochemical

functions of humans body system,which include the organs, and the

cells of which they are composed.


20/99

Nervous system

Consists of the Central Nervous System (which is the brainand spinal cord) and peripheral nervous system

The brain is the organ of thought, emotion, and sensoryprocessing, and serves many aspects of communication andcontrol of various other systems and functions.

The special senses consist of:

Vision > eye

Hearing > ear Taste > tongue

Smell > nose

The eyes, ears, tongue and nose gather information about thebody's environment.


21/99

Musculoskeletal System

Consists of the human skeleton(which includes bones, tendons,ligaments and cartilage) and

attached muscles.

It gives the body basic structureand the ability for movement. Inaddition to their structural role,the larger bones in the body

contain bone marrow, the site ofproduction of blood cells.

Also, all bones are major storagesites for calcium and phosphate.


22/99

Gastrointestinal system

Consists of the mouth,

esophagus, gut (small and large

intestines), and rectum, as well

as the liver, pancreas,

gallbladder, and salivary glands.

It converts food into small,

nutritional, non-toxic molecules

for distribution by thecirculation to all tissues of the

body, and excretes the unused

residue.


23/99

Circulatory System

Consists of the heart and bloodvessels (arteries, veins,capillaries).

The heart propels thecirculation of the blood, whichserves as a "transportationsystem" to transfer oxygen,fuel, nutrients, waste products,

immune cells, and signallingmolecules (i.e., hormones)from one part of the body toanother.

The blood consists of fluid that

carries cells in the circulation,including some that move from


24/99

Circulatory System


25/99

FUNCTIONS OF THE

CIRCULATORY SYSTEM

Oxygen and nutrient (fuel) transport to the cells.

Transport of metabolic waste products to organ

removal sites.

Assists in temperature regulation.


26/99

Components of theCirculatory System


27/99

Plasma

O2

Red Blood Cell

CO2

CO2 O2

CO2

O2

hemoglobinmolecule

Blood transport ofO2 and CO2

O2 molecule


28/99

Metabolic System


29/99

Respiratory System

Respiratory system

consists of the nose,

nasopharynx, trachea,an lungs

It brings oxygen from

the air and excretes

carbon dioxide and

back into the air.


30/99

The respiratory system consists of passages andorgans that bring atmospheric air into the body

30


31/99

Respiratory System


32/99

ELO #4

ACTION: Select the functions and types of

respiration.

CONDITION: Given a list.

STANDARDS: IAW FM 3-04.301.


33/99

FUNCTIONS OF THE

RESPIRATORY SYSTEM

Intake of Oxygen [O2]

Removal of Carbon Dioxide [CO2]

Maintenance of body heat balance

Maintenance of body acid base balance [pH]


34/99

Phases of Respiration

Active PhaseINHALATION

Passive PhaseEXHALATION

Breathing in Breathing out


35/99

COMPONENTS OF THE RESPIRATORY SYSTEM

Nasal/Oral

pharynx

Trachea

Bronchi

Bronchiole

Alveolar

DuctsAlveoli


36/99

Law of Gaseous Diffusion

Gas molecules of higher pressure move in thedirection of gas molecules of a lower pressure

PO2 = 100mmHg PO2 = 40mmHg

PO2 = 70 mmHg PO2 = 70 mmHg


37/99

Blood GasExchange

PCO2 = 46 mm

PO2 = 100 mmPCO2 = 40 mm

PO2 = 40 mm

PO2 = 100 mm

PCO2 = 40 mmPCO2 = 46 mm

PO2 = 1 - 60 mm

Arterial Capillary

Hemoglobin Saturation 98%

O2

O2

CO2

O2

CO2

O2

Venous Capillary

Hemoglobin Saturation 75%

Tissue Alveoli


38/99

Oxygen transport in the blood:

dependent on thepartial pressure of oxygen.

pO2


39/99

PERCENT COMPOSITION OFTHE ATMOSPHERE REMAINS

CONSTANT

BUT PRESSURE

DECREASES

WITH ALTITUDE


40/99

SIGNIFICANT PRESSURE ALTITUDES

ALTITUDE PRESSURE

FEET mm/HG ATMOSPHERES

0 760 1

18,000 380 1/2

34,000 190 1/4

48,000 95 1/8

63,000 47 1/16


41/99


42/99

Physical characteristics of the atmosphere

The atmosphere is like an ocean of air that surrounds thesurface of the Earth.

It is a mixture of water and gases.The atmosphere extends from the surface of the Earth to

about 1,200 miles in space.

Gravity holds the atmosphere in place.

The atmosphere exhibits few physical characteristics;however, it shields the inhabitants of the Earth fromultraviolet radiation and other hazards in space.

Without the atmosphere, the Earth would be as barren asthe moon.

42


43/99

The atmosphere consists of several concentric layers, each

displaying its own unique characteristics.

Each layer is known as a sphere.

Thermal variances within the atmosphere help define thesespheres, offering aviation personnel an insight into atmosphericconditions within each area.

Between each of the spheres is an imaginary boundary, knownas a pause.

43


44/99

Troposphere

Troposphere extends from sea level to about 26,405 feet

over the poles to nearly 52,810 feet above the equator

Stratosphere

Tropopause to about 158,430 feet (about 30 miles)

Mesosphere

Stratopause to an altitude of 264,050 feet (50 miles) Thermosphere

From 264,050 feet (50 miles) to about 435 miles above

the Earth

44


45/99

45

Standard Pressure and Temperature Values at 40 Degrees Latitude for Specific Altitudes


46/99

Composition of the Air

78 Percent Nitrogen N2

21 Percent Oxygen

1 Percent Other

.03 percent CO2


47/99

Partial Pressure

(Daltons Law)760 mm Hg

47 --- mm/Hg

95 ---

190 ---

380 ---

523 ---

760 ---

21%O

2

78% N2


48/99

Boyles Law

This law states that the volume of a gas is inversely proportional to thepressure (temperature remaining constant). This applies to all gases.V1/V2 = P2/P1 (V1 is the initial volume of the gas, V2 is the finalvolume, P1 is the initial pressure on the gas volume, and P2 is the finalpressure).

In other words, if the pressure of the gas decreases with thetemperature unchanging, then its volume increases and vice versa (Fig.3-2). In dealing with gas expansion in the body, a correction must bemade for the ever-present water vapor; therefore, the formula nowbecomes: V1/V2 = (P247 mm Hg)/(P146 mm Hg) (Fig. 3-3). Water-

vapor pressure at body temperature is 47 mm Hg. Such characteristics applied to the body explain The expansion of

gases trapped within such moist areas as the middle ears, sinuses,stomach, and intestines.

These are all actual or potential cavities within which moist air ispresent and can become trapped and expand like any other gas; hence,

the physiological topic of trapped gases, which will be discussed inCha ter 5 re ardin altitude h siolo .


49/99

Charles Law

Charles Law states that the volume of gas is directly proportional to the temperature (pressureremaining constant).

This applies to all gases. This law has no direct physiological significance because body temperatureremains fairly constant.

It does, however, explain the fact that pressure within supplemental oxygen containers will decrease

if the ambient temperature surrounding the storage container decreases, even when no oxygen hasbeen used, such as at altitude.

Daltons Law

Since the atmosphere is a mixture of gases, and each gas has its own pressure at any giventemperature within a given volume, it is important to also be familiar with the physics of thecombined pressures.

Daltons Law states that the total pressure of a gas mixture is the sum of the individual pressure (alsocalled partial pressure) that each gas would exert if it alone occupied the whole volume.

Figure 3-3 The effect of water on gas expansion.

Or expressed mathematically: PT= P1 + P2 + Ps + Pn; where PTis the total pressure of the mixtureof gases and the P value is the partial pressure of each gas, which is determined by multiplying thepercentage of the individual gas times the total pressure.


50/99

Physiological Divisions Of The

Atmosphere

Ph i l Di i i f th At h


51/99

TROPOSPHERE

Sea level to flight level 300 -

600 depending on temperature,

latitude and season.

Physical Divisions of the Atmosphere

STRATOSPHERE

IONOSPHERE

EXOSPHERE

MOUNT EVEREST 29,028 FEET

1200 miles

600 miles

50 miles

Tropopause

Physiological Zones of the


52/99

Physiological Zones of the

Atmosphere

EFFICIENT ZONE: Sea level to 10,000 feet

SPACE EQUIVALENT ZONE: 50,000 feet and above

DEFICIENT ZONE: 10,000 to 50,000 feet18,000 ft

63,000 ft


53/99

Composition of the Air

78 Percent Nitrogen N2

21 Percent Oxygen

1 Percent Other

.03 percent CO2


54/99

Hypoxia

Hyperventilation

Pressure effect changes

Trapped Gas Disorders

Evolved-Gas Disorders

Visions 54


55/99

GENERAL EFFECTS ON THE


56/99

GENERAL EFFECTS ON THE

HUMAN BODY


57/99

57

Altitude Physiology


58/99

The physiology of oxygen in the body 50

Review of respiration physiology 51

Carbon monoxide and ozone 67

Decompression of cabin altitude 68

Trapped gases 70

Evolved gas disorders 75


59/99

Hypoxia

Hyperventilation

Pressure effect changes

Trapped Gas Disorders

Evolved-Gas Disorders

Visions

Gravity Force G

59


60/99

Contents

Types of Hypoxia

Causes of Hypoxia

Effect of Hypoxia

Overcoming Hypoxia


61/99

Hypoxia

State ofoxygen [O2] deficiency

in the blood cells and tissuessufficient to cause

impairment of function.


62/99

Types of Hypoxia

Hypemic

Stagnant

Histotoxic

Hypoxic

H i H i


63/99

ReducedpO2in the lungs

(highaltitude)

Body tissue

Redblood cells

Hypoxic Hypoxia

A deficiencyin Alveolaroxygen

exchange


64/99

Hypoxic hypoxia

Hypoxic hypoxiaoccurs when not enough oxygen isin the air or when decreasing atmospheric pressuresprevent the diffusion of O2 from the lungs to thebloodstream.

Aviation personnel are most likely to encounter thistype at altitude. It is due to the reduction of the O2 athigh altitudes

64

H i H i


65/99

An oxygendeficiencydue toreduction inthe oxygen

carryingcapacity ofthe blood+

+

+

+

++

+

++

+

+

+

+ ++

Hypemic Hypoxia


66/99

Hypaemic, or anaemic,

Hypaemic, or anaemic,hypoxia is caused by a reductionin the oxygen-carrying capacity of the blood.

Anaemia and blood loss are the most common causes ofthis type.

Carbon monoxide, nitrites, and sulpha drugs also causethis hypoxia by forming compounds with haemoglobinand reducing the haemoglobin that is available tocombine with oxygen.

66


67/99

Reducedbloodflow

Bloodmovingslowly

Adequateoxygen

Red blood cells

not replenishingtissue needsfast enough

Stagnant

Hypoxia


68/99

stagnant hypoxia

In stagnant hypoxia, the oxygen-carrying capacity ofthe blood is adequate but, circulation is inadequate.

Such conditions as heart failure, arterial spasm, andocclusion of a blood vessel predispose the individual tostagnant hypoxia.

More often, when a crew member experiences extremegravitational forces, disrupting blood flow and causingthe blood to stagnate.

68

Histotoxic Hypoxia


69/99

Red blood cellsretain oxygen

Inability of thecell to acceptor use oxygen

Poisoned tissue

Adequateoxygen

Histotoxic Hypoxia


70/99

This type results when there is interferencewith the use of O2 by body tissues.

Alcohol, narcotics, and certain poisonssuchas cyanideinterfere with the cells ability touse an adequate supply of oxygen.

70

Hypoxia Symptoms


71/99

Hypoxia Symptoms

what you feel

(subjective)Air hunger

Apprehension

Fatigue

Nausea

Headache

Dizziness

Denial

Hot & Cold Flashes

Euphoria

Belligerence

Blurred Vision

Numbness

Tingling


72/99

Symptoms vary from one person to another and,therefore, are subjective.

Aviation personnel commonly experience mild hypoxia ataltitudes at orabove 10,000 feet.

Those who fly must be able to recognize the possiblesigns and symptoms because the onset of hypoxia issubtle and produces a false sense of well-being.

Crew members are often engrossed in flight activitiesand do not readily notice the symptoms of hypoxia.

However, most individuals experience two or threeunmistakable symptoms or signs that cannot beoverlooked. 72


73/99

73


74/99

Susceptibility to hypoxia varies with individuals

Several factors determine individual susceptibility

1. O2 Deficiency - Onset Time and Severity

The onset time and severity of hypoxia vary with the

amount of oxygen deficiency.

Crew members must be able to recognize hypoxia andimmediately determine the cause.

74


75/99

2. Self-Imposed Stress

Self-imposed stressors, such as tobacco and alcohol,

increase the physiological altitude.

Physiological Altitude

An individuals physiological altitude, the altitude that the

body feels, is as important as the true altitude of a flight.

75


76/99

3. Smoking

The haemoglobin molecules of RBCs have a 200- to300-times greater affinity for carbon monoxide than foroxygen

Cigarette smoking significantly increases the amountof CO carried by the haemoglobin of RBCs; thus, itreduces the capacity of the blood to combine withoxygen

Smoking 3 cigarettes in rapid succession or 20 to 30cigarettes within 24 hours before a flight may saturatefrom 8 to 10 percent of the haemoglobin in the blood.

76


77/99

77


78/99

4. Alcohol.

Alcohol creates histotoxic hypoxia. For example, an individual who has

consumed 1 ounce of alcohol may have a physiological altitude of 2,000feet

5. Individual Factors Metabolic rate, diet, nutrition, and emotions greatly influence an

individuals susceptibility to hypoxia.

6. Ascent Rate (Climb Rate) Rapid climb rates affect the individuals susceptibility to hypoxia. High

altitudes can be reached before the crew member notices serioussymptoms.

7. Exposure Duration The effects of exposure to altitude relate directly to an individuals lengthof exposure. Usually, the longer the exposure, the more detrimental theeffects. At

higher the altitude, the shorter the exposure time required beforesymptoms of hypoxia occur.

78


79/99

8. Ambient Temperature

Extremes in temperature usually increase the metabolic rate of thebody. A temperature change increases the individuals oxygen

requirements while decreasing the tolerance of the body to hypoxia. With these conditions, hypoxia may develop at lower altitudes than

usual.

9. Physical Activity When physical activity increases, the body demands a greater

amount of oxygen. This increased oxygen demand hypxia to takeeffect faster

10. Physical Fitness

An individual who is physically conditioned will normally have ahigher tolerance to altitude problems than one who is not. Physical fitness raises an individuals tolerance ceiling.

79


80/99

In aviation, the most importanteffects of hypoxia are those related,either directly or indirectly, to thenervous system

Nerve tissue has a heavyrequirement for oxygen. Brain tissueis one of the first areas affected by

an oxygen deficiency

A prolonged or severe lack ofoxygen destroys brain cells.

The expected performance time isfrom the interruption of the oxygen

supply until the crew member losesthe ability to take corrective action.

80

Aviators Performance Time VS Height


81/99

Hypoxia Signs


82/99

Hyperventilation

Cyanosis

Mental confusion

Poor Judgment

Lack of muscle coordination

yp gwhat we see in you

(objective)

St f H i


83/99

Stages of Hypoxia

Indifferent Stage

Compensatory Stage

Disturbance Stage

Critical Stage


84/99

Indifferent Stage

Altitudes:

Air: 0 - 10,000 feet

100% O2: 34,000 - 39,000 feet

Symptoms: decrease in night vision

@ 4000 feet acuity

color perception

Compensatory Stage


85/99

Compensatory Stage

Altitudes:Air: 10,000 -

15,000 feet

100% O2: 39,000 - 42,000

feet

Symptoms: impaired efficiency,drowsiness, poor judgment and

decreased coordination


86/99

CAUTION!!!!

Failure to recognize yoursigns and symptoms may

result in an aircraft mishap.

Di t b St


87/99

Disturbance Stage

Altitudes

Air: 15,000 - 20,000 FEET

100% O2: 42,000 - 44,800 FEET

Disturbance Stage


88/99

Disturbance Stagesymptoms

Memory

Judgment

Reliability

Understanding

Coordination

Flight Control

Speech

Handwriting


89/99

Time of Oxygen

1 Minute

2 Minutes

3 Minutes

4 Minutes

5 Minutes

6 Minutes

Put Back on Oxygen


90/99

Disturbance Stage

Signs

Hyperventilation

Cyanosis


91/99

Critical Stage

Altitudes

Air: 20,000 feet and above

100% O2: 44,800 feet and above

Signs: loss of consciousness,convulsions and death

Factors modifying hypoxia


92/99

y g ypsymptoms

Pressure altitude

Rate of ascent

Time at altitude

Temperature

Physical activity

Individual factors

Physical fitness

Self-imposed stresses

DEATH


93/99

keep self imposed stresses out of the aircraft

DEATH

Drugs

Exhaustion

Alcohol

Tobacco

Hypoglycemia

ALCOHOL


94/99

ALCOHOL


95/99

Expected performance time for a crew member

flying in a pressurized cabin is reducedapproximately one-halffollowing

loss of pressurization such

as in a:

RDRapidDecompression

Expected Performance


96/99

FL 430 & above 9-12 secondsFL 400 15 - 20 secondsFL 350 30 - 60 seconds

FL 300 1 - 2 minutes

FL 280 2 1/2 - 3 minutes




Expected Performance

Times

Hypoxia


97/99

Hypoxia

Prevention

Limit time at

altitude

100% O2


98/99


99/99

Individuals who exhibit signs and symptoms of hypoxiamust be treated immediately.

Treatment consists of giving the individual 100 percent

oxygen.

If oxygen is not available, descent to an altitude below10,000 feet is mandatory.

When symptoms persist, the type and cause of thehypoxia must be determined and treatment administeredaccordingly.

Lecture 2- Physiology and Effects of Flight

Documents

Transcript of Lecture 2- Physiology and Effects of Flight