LECTURE 2: ATMOSPHERE & HYPOXIAAVIATION HUMAN FACTOR: AHF 2203

AVIATION MANAGEMENT COLLEGE

SIR MOHD ‘ARIFF BIN ABDUL JALIL

Review on last chapter

Definition of Physiology and Flight Physiology.

Importance of Flight Physiology. Basic Concept of The Nervous

System. Basic Concept of The Respiratory

System. Basic Concept of The Circulatory

System.

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Learning Outcomes

At the end of this session, student should be able to: Know that pressure plays the

important role during altitude changes

Classify the types of hypoxia, it causes, symptoms, and prevention steps through the explanation.

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Air is one of the primary things that makes life on Earth possible.

Air is a synonym for atmosphere.

The Earth’s atmosphere or air is made up of a variety of gases and other particles.

Earth’s Atmosphere4

What is the Atmosphere??

Layer of gases surrounding the planet Earth that is retained by Earth's gravity.

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Layers (Structure) of Atmosphere

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Temperature will decrease constantly with altitude.

75% of weight of atmosphere.

Contains almost all weather Altitude (height) vary with:

Latitude: lower at poles and higher at equatorial

Seasons: higher in summer than winter

Almost all clouds in this layer.

Almost commercial aircrafts fly in this layer.

Troposphere7

Very small increase in temperature (almost constant) except at the top where temperature is zero at 50 kms.

Little water vapor @ turbulence

Stratosphere8

Functions of the Atmosphere

Source of oxygen and carbon dioxide Protection for the human on the Earth

from the harmful cosmic ray, solar radiation and ultraviolet (UV) ray.

Source of rain Maintains the temperature and

climate that sustain life on earth

Variation in Atmosphere

The earth’s atmosphere varies in Temperature Pressure Density Humidity

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Atmospheric Pressure

Atmospheric pressure is the combined weight of all the atmospheric gases, creating a force upon the surface of the earth – the cause of this force is gravity.

The atmospheric pressure can be measured in force / unit area (Pounds per square inch [Psi] or Millimeters of mercury [mm/Hg])

The standard atmospheric pressure at sea level is 760 mm/Hg.

Pressure and Temperature Decrease

with AltitudeAltitude (Feet)

Pressure (mm/ Hg)

Temperature (degree

Celsius)

0 760 15.0

18,000 380 -5.3

34,000 190 -62.3

48,000 95 -67.3

63,000 47 -67.04

Pressure & Temperature

Air Pressure At sea level, the air pressure is about At sea level, the air pressure is about 760

mm/Hg. As the As the altitude increasesaltitude increases, the air , the air

pressure decreases pressure decreases (and there is (and there is less less oxygenoxygen to breathe). to breathe).

Temperature As we As we ascendascend from the surface, the from the surface, the

temperature falls temperature falls steadily with altitude.steadily with altitude. Temperature decreases at about 2°C per Temperature decreases at about 2°C per

1,000 feet .1,000 feet .

Physiological Zones of the Atmosphere Atmosphere can be divided into 2

physiological zones, which are efficient and deficient. Efficient zone: Sea level to 10,000 feet Deficient zone: 10,000 to 50,000 feet

These zones can affect us medically and physiologically.

Physiologicalrelating to the way that living things functions

HYPOXIA

Definition of Hypoxia

A condition that results from an insufficient amount of oxygen (O2) in the body. Hypoxia can occur at any altitude and it is accumulative among the types of hypoxia.

Syndromes of lack of oxygen in blood

Effect mainly the brain and other nervous system

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CRITICAL THINKINGWHAT WILL HAPPEN DUE TO LACK

OF OXYGEN IN BLOOD?WHY BRAIN IS AFFECTED THE

MOST?WHAT ARE THE EFFECTS IF BRAIN

IS AFFECTED?

How it can be happened??(Physiological Process)

Hemoglobin is primary transport to carry oxygen through blood.

The ability of hemoglobin to carry oxygen is called as: Blood Oxygen Saturation (normally 95%-98% at sea level). It is measurable as we ascend.

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Time of Oxygen

1 Minute

2 Minutes

3 Minutes

4 Minutes

5 Minutes

6 Minutes

Put Back on Oxygen

Experiment on Removing Oxygen

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