Altitude Physiology

Question 1

What are the physical divisions of the atmosphere?

Answer 1

Troposphere - Extends to an Alt. of 30,000 ft. at the poles and 60,000 ft. at the equator Tropopause - boundary between troposphere and stratosphere Stratosphere - tropopause to about 50 miles upward. Ionosphere - end of stratosphere upward to 600 miles Exosphere - end of ionosphere to about 1200 miles (true space)

Question 2

What are the physiological zones of the atmosphere

Answer 2

Efficient zone Deficient zone Space equivalent zone

Question 3

Efficient zone

Answer 3

sea level to 10,000 ft

Question 4

Deficient zones

Answer 4

10,000 ft to 50,000 ft

Question 5

Space equivalent zone

Answer 5

above 50,000 ft

Question 6

What are the functions of the circulatory system?

Answer 6

Transports O2 and nutrients to cells throughout the body Transports metabolic waste products to organ removal sites Assists in temperature regulation Acid-base balance

Question 7

What carries O2 to cells

Answer 7

red blood cells

Question 8

What are the functions of respiration?

Answer 8

Provide O2 to cells, Remove carbon dioxide from cells Assist in maintaining body temperature, Assist in maintaining body acid-base balance

Question 9

Inhalation

Answer 9

The active phase of respiration. Movement of air into the lungs when the chest wall expands and the diaphragm moves downward.

Question 10

Exhalation

Answer 10

The passive phase of respiration. Movement of air out of the lungs when the chest wall collapses and the diaphragm relaxes.

Question 11

What happens to respiration during pressure breathing at altitude

Answer 11

The active and passive phases of respiration are reversed. In some indivduals, this can lead to hyperventilation and unconsciousness

Question 12

Hypoxia

Answer 12

Oxygen deficiency sufficent to impair performance

Question 13

What are the four types of Hypoxia

Answer 13

Hypemic Stagnant Histotoxic Hypoxic

Question 14

Hypemic Hypoxia

Answer 14

Reduction in O2 carrying capability of red blood cells; e.g. carbon monoxide

Question 15

Stagnant Hypoxia

Answer 15

Reduction in blood flow; e.g. positive G maneuvers

Question 16

Histotoxic Hypoxia

Answer 16

Interference with the use of O2 by the body tissues; e.g. cyanide poisoning

Question 17

Hypoxic Hypoxia

Answer 17

Insufficient pressure of O2 in the air; e.g. flying at altitude

Question 18

Symptoms

Answer 18

What you feel

Question 19

Signs

Answer 19

What you see in others

Question 20

Stages of Hypoxia

Answer 20

• Indifferent stage
• Compensatory stage
• Disturbance stage
• Critical stage

(ICDC)

Question 21

Indifferent stage

Answer 21

sea level to 10,000 ft, usually no symptoms noted in a healthy individual.

Question 22

What is the only significant effect of mild hypoxia at the indifferent stage?

Answer 22

Night vision deteriorates at about 4,000ft.

Question 23

Compensatory stage

Answer 23

10,000 to 15,000 ft;

mild effects begin to appear, but the individual can usually overcome the effects or compensate for the deficits

Question 24

Disturbance stage

Answer 24

15,000 to 20,000 ft;

most of the symptoms of hypoxia will appear, and will increase in severity with absolute altitude, time at altitude, and rate of ascent

Question 25

Critical stage

Answer 25

20,000 ft and above severe effects: loss of consciousness, convulsions, and death

Question 26

What is hyperventilation

Answer 26

Abnormal loss of CO2 from the blood

Question 27

Causes of hyperventilation

Answer 27

Causes are usually: - emotional; fear, apprehension, excitement - pressure breathing, - hypoxia

Question 28

Symptoms of Hypoxia

Answer 28

Symptoms are observable by the individual aircrew member. They vary from one person to the next: Air hunger or breathlessness / Apprehension (anxiety) Fatigue / Nausea / Headache / Dizziness / Hot and cold flashes / Euphoria / Belligerence (anger) Blurred vision Tunnel vision / Numbness / Tingling / Denial

Question 29

Signs of Hypoxia

Answer 29

Signs are observable by the other aircrew members Increased rate and depth of breathing /Cyanosis /Mental confusion / Poor judgment / Loss of muscle coordination Unconsciousness / Slouching

Question 30

Symptoms of Hyperventilation

Answer 30

similar to those of hypoxia: Tingling sensations /Muscle spasms /Hot and cold sensations / Visual impairment / Dizziness / Unconsciousness

Question 31

Differentiate between hyperventilation and hypoxia

Answer 31

Altitude: Above 10,000 ft, assume hypoxia: Below 10,000 ft, assume hyperventilation Symptoms: Cyanosis only seen with Hypoxia Muscle Spasms only seen with Hyperventilation

Question 32

What is the treatment of hyperventilation / hypoxia.

Answer 32

Treatment Above 10,000 feet- assume hypoxia and treat accordingly. 100% O2 / Descend to a safe altitude. Below 10,000 feet- assume hyperventilation and treat accordingly. Voluntary reduction in rate and depth of respiration is necessary to accomplish this task./ Reading or repeating a checklist in most cases can treat hyperventilation.

Question 33

Your co-pilot has pain in one tooth, what is it and what do you do?

Answer 33

Land and seek dental care. it is Barodontalgia (trapped gas disorders of the teeth).

Question 34

What is the treatment for sinus trapped gas dysbarism?

Answer 34

Stop descent of aircraft and attempt to clear by valsalva

Question 35

A mixture of gases that surrounds the Earth's surface is the \_\_\_\_\_\_\_\_\_\_.

Answer 35

atmosphere

Question 36

The ___________ is the domain of weather, winds, turbulence and convection.

Answer 36

troposphere

Question 37

The physiological zones of the atmosphere are \_\_\_\_\_\_\_\_\_\_, _________ and __________ zones.

Answer 37

efficient, deficient, space equivalent

Question 38

Oxygen makes up ________ % of gas in the atmosphere.

Answer 38

21

Question 39

\_\_\_\_\_\_\_\_\_ is the fluid part of the blood composed mainly of salt, water and proteins.

Answer 39

Plasma

Question 40

\_\_\_\_\_\_\_\_ transport approximately _______ % of all O2 in the body.

Answer 40

Red blood cells, 98,5

Question 41

\_\_\_\_\_\_\_\_\_ is a process by which a living organism exchanges gases with its environment.

Answer 41

respiration

Question 42

Respiration is an __________ process that occurs in two phases, the __________ phase and the _________ phase.

Answer 42

involuntary inhalation/active exhalation/passive

Question 43

What is the mnemonic for the stages of hypoxia?

Answer 43

ICDC

Question 44

\_\_\_\_\_\_\_\_ hypoxia results when there is interference with the use of O2 by body tissue.

Answer 44

Histotoxic

Question 45

True of false: Hypoxia can occur at any altitude.

Answer 45

True!

Question 46

\_\_\_\_\_\_\_\_\_\_ is an excessive rate and depth of respiration leading to abnormal loss of O2.

Answer 46

Hyperventilation

Question 47

The __________ stage of hypoxia is associated with altitudes of 10,000 - 15,000 feet.

Answer 47

compensatory