Hypoxia, Hyperventilation, the eye and the ear

Question 1

What is the composition of air?

Answer 1

78% Nitrogen, 21% oxygen and 1% other gases

Question 2

What is Boyle’s law?

Answer 2

At a constant temperature the volume of a gas is inversely proportional to its pressure

Question 3

What is Charle’s law?

Answer 3

The volume of a fixed mass of gas held at a constant pressure varies directly with the absolute temperature

Question 4

What is Dalton’s law?

Answer 4

The total pressure of the gas mixture is equal to the sum of its partial pressure

Question 5

What is Henry’s law?

Answer 5

At equilibrium the amount of gas dissolved in a liquid is proportional to the gas pressure

Question 6

What is Hypoxia?

Answer 6

A lack of sufficient oxygen to meet the demands of the body

Question 7

What is an early symptom of Hypoxia?

Answer 7

Common sense tend to be diminished

Question 8

What are some symptoms of Hypoxia?

Answer 8

Impaired thinking and judgement
slow reactions
mental and muscular in-coordination
diminished vision and hearing
impaired memory

Question 9

Who is affected earlier with Hypoxia?

Answer 9

Smokers

Question 10

What is the effect of altitude below 6000ft?

Answer 10

No Supplemental oxygen supply

Question 11

What is the effect of altitude below 10000ft?

Answer 11

Normal activities can be carried out

Question 12

What is the effect of altitude at 14000ft?

Answer 12

Significant lack of judgement and concentration

Question 13

What is the effect of altitude at 18000ft?

Answer 13

Total lack of judgement and concentration

Question 14

What happens to oxygen pressure with increase in altitude?

Answer 14

Oxygen pressure decreases

Question 15

Does the proportion of the air mixture change with the change in altitude?

Answer 15

No

Question 16

What is Hyperventilation?

Answer 16

Breathing in excess of the metabolic needs of the body

Question 17

What are the main symptoms of Hyperventilation?

Answer 17

Dizziness,
Increased sensation of body heat
Tingling sensation in fingers and toes
Increased heart rate
Nausea
Blurred vision

Question 18

How many hours is recommended after a controlled ascent dive ( decompression dive)?

Answer 18

24 hours

Question 19

How many hours is recommended after a controlled ascent before flight to a cabin pressure altitude of up tp 8000ft?

Answer 19

12 hours

Question 20

What is the recommended waiting time for pressure altitudes above 8000ft for any type of dive?

Answer 20

24 hours

Question 21

What is the cornea?

Answer 21

the transparent part of the outer covering of the eyeball which overlies the pupil

Question 22

Where does light enter the eye from?

Answer 22

The cornea

Question 23

What is a pupil?

Answer 23

Central Aperture of the iris

Question 24

What is the function of the pupil?

Answer 24

Control the amount of light entering the interior of the eye

Question 25

What is behind the iris?

Answer 25

The lens

Question 26

What is a lens?

Answer 26

A transparent biconvex structure which focuses the light rays onto the retina at the back of the eye

Question 27

What is the function of the retina?

Answer 27

Convert the images made by the received light into electrical signals whicha re then sent to the brain by the optic nerve

Question 28

What does Ciliary muscles and ligaments do?

Answer 28

Modify lens curvature

Question 29

What effects vision in flight?

Answer 29

Amount of light
Contrast of an object against its background
Size and contours of an object against its background
The distance an object is from the eye
The relative motion of of a moving object
Atmospheric conditions ( dust smoke mist rain)

Question 30

What is the blind spot?

Answer 30

Where the optic nevre is, image is not formed here

Question 31

What kind of illusion might an up sloping runway give?

Answer 31

The aircraft is higher than it is and lead to a lower approach

Question 32

What kind of illusion might a down sloping runway give?

Answer 32

The aircraft is lower than it is and lead to a higher approach

Question 33

What makes runway illusions worse?

Answer 33

Lack of visual ground aids

Question 34

What does the ear flaps do?

Answer 34

Collects sounds and directs them along the ear canal to the ear drum

Question 35

What causes the drum to vibrate?

Answer 35

Sounds which are small fluctuations in air pressure

Question 36

What is the eustachian tube?

Answer 36

Equalizes the ear pressure and connect the ear with the back of the throat

Question 37

What is needed for the drum to be sensitive?

Answer 37

The air in the middle ear must be the same pressure as the air in the outer ear

Question 38

Where is the organ of balance?

Answer 38

In the ear

Question 39

What does the organ of balance consist of?

Answer 39

3 inter-connected semi-circular canals which contain fluid

Question 40

What happens when the head moves?

Answer 40

The relative movements between the fluid and the canal displaces the receptor which sends a signal to the brain via the auditory nerve

Question 41

How are the semi circular motion sensing systems arranged?

Answer 41

At right angles to each other in the roll ptch and yaw axis

Question 42

What does the motion sensing system detect?

Answer 42

Angular acceleration , gravity and linear acceleration

Question 43

What is Aerotitis?

Answer 43

when the ear becomes distended and inflamed as the pressure in the ear is not readily equalized

Question 44

How can the ventilation of the middle ear be brought?

Answer 44

yawning and swallowing

Question 45

Why is it not recommended to fly if you have a cold or other respiratory infection?

Answer 45

Because the tissue around the nasal end of the Eustachian tube is likely to be swollen

Question 46

Why should pilots not fly when suffering from head colds?

Answer 46

Due tp risk of damage to ear drums