Aviation Physiology

Question 1

What is aviation physiology ?

Answer 1

Health factors and physical effects linked to flying

Question 2

Dehydration

Answer 2

• Critical loss of water from the body

Causes:
* Hot Flight Decks
* Increasing Altitude
* Humidity

Question 3

Hypoxia

Answer 3

• Not enough/reduced oxygen in the body

Question 4

Types of Hypoxia

Answer 4

– Hypoxic hypoxia
– Hypemic hypoxia
– Histotoxic hypoxia
– Stagnant hypo

Question 5

Hypoxic hypoxia

Answer 5

– Insufficient oxygen available to the body

Causes:
* A blocked airway
* Underwater
* Being at high altitude

Question 6

Hypemic Hypoxia

Answer 6

• oxygen deficiency in the blood

Causes:
– Physical injury resulting in blood loss
– Blood Donation
– Sickle Cell Anemia
– Smoking
– Carbon Monoxide Poisoning

Question 7

Histotoxic Hypoxia

Answer 7

The cells are unable to use the oxygen
“Histo” – tissues/cells
“Toxic” - poisonous

Causes:
– Alcohol
– Drugs

Question 8

Stagnant Hypoxia

Answer 8

– The blood is unable to flow
– Cells are starved of oxygen

Causes:
– Extreme cold temp.
– Shock
- Cardiac problem

Question 9

Symptoms of hypoxia

Answer 9

• CYANOSIS (BLUE FINGERNAILS AND LIPS)
• Headache
• Decreased reaction time
• Impaired judgment
• Euphoria
• Visual impairment
• Drowsiness
• Lightheaded or dizzy sensation
  *Tingling in fingers and toes
• Numbness

Question 10

Treatment of hypoxia

Answer 10

• Fly at lower altitudes
• Use supplemental oxygen
  – 10,000ft day
  – 5,000ft night

Question 11

Why is it that supplemental oxygen is higher in day rather than night

Answer 11

because of the process called photosynthesis. During the day the plants produce byproducts of oxygen from carbon dioxide absorb from the energy of sun. Since there is no light during the night. oxygen production has a limit thus having lower altitude during night flight

Question 12

Time of Useful Consciousness

Answer 12

The maximum time a pilot has to make rational decisions

Time of useful consciousness by altitude:
45000ft - 9 to 15 sec
40000ft - 15 to 30 sec
35000ft - 30 to 60 sec
30000ft - 1 to 2 min
28000ft - 2 1/2 to 3 min
25000ft - 3 to 5 min
22000ft - 5 to 10 min
20000ft - 30 min or more

Question 13

Carbon Monoxide Poisoning

Answer 13

• Caused by a faulty exhaust system or smoking
• Susceptibility increases with increased altitude

Question 14

Symptoms of Carbon Monoxide Poisoning

Answer 14

• LOSS OF MUSCULAR POWER
• Deterioration in vision
• Impaired judgment
• Personality change
• Impaired memory
• Slower breathing rate
• Cherry-red complexion
• headache, dizziness and nausea Convulsions
• COMA OR EVENTUALLY DEATH

Question 15

Hyperventilation

Answer 15

• An excessive loss of Carbon Dioxide from the body

Causes:
– Emotional stress
– Fright
– Pain
– Excitement

Question 16

Symptoms of Hyperventilation

Answer 16

• MUSCLE SPASM
• Visual impairment
• Unconsciousness
• Lightheaded or dizzy sensation
• Tingling in fingers and toes
• Numbness
• Hot and cold sensation

Question 17

Treatment for hyperventilation

Answer 17

• Breathe normally to restore proper carbon dioxide level in the body
• Breathing into a paper bag
• Recovery is usually rapid

Question 18

Barotrauma

Answer 18

• Severe pain caused by increasing cabin altitude due to expansion of gas inside the body such as stomach, intestines, sinuses, middle ear or in decaying tooth

Question 19

Barotrauma of the ear

Answer 19

Caused by pressure changes within the ear
canal during climbs and descents

• Valsalva Maneuver – This procedure forces air through the Eustachian tube into the middle ear.

Question 20

Barotrauma of the sinuses

Answer 20

Intense pain due to sinus block

Question 21

Decompression sickness

Answer 21

• the nitrogen is forced to leave the solution too rapidly; bubbles form in different areas of the body.

Question 22

Symptoms of decompression sickness

Answer 22

• The Bends
• Skin Manifestation
• Pulmonary (chokes)
• Neurological Manifestation

Question 23

The bends

Answer 23

• Gas dissolves out in
  the joints, muscles and tendons

Signs & Symptoms:
- Localized deep pain (mild
to excruciating)
- Active and passive motion
of the join aggravates the pain

Question 24

Skin manifestation

Answer 24

• Nitrogen dissolves out into the skin

Signs & Symptoms:
- Itching
- Swelling of the skin
- Tiny-scar like depressions

Question 25

Pulmonary (Chokes)

Answer 25

– Nitrogen bubbles form in the lungs – The bubbles can block the normal flow of blood resulting in serious medical conditions Signs & Symptoms: - Burning deep chest pain - Shortness of breath - Constant Dry cough

Question 26

Neurological Manifestation

Answer 26

– Nitrogen bubbles can be transported to the brain, spinal cord and nerves Signs & Symptoms: - Headache - Dizziness - Confusion - Unconsciousness

Question 27

Decompression sickness prevention

Answer 27

* Wait 12 hours after a dive which does not require a controlled ascent for flight below 8,000 feet. * Wait 24 hours after a dive which required a controlled ascent for flight below 8,000 feet. * Wait 24 hours after a dive to climb to an altitude above 8,000 feet.

Question 28

Spatial Disorientation

Answer 28

- the lack of orientation with regards to the position, attitude, or movement of the airplane in space

Question 29

Sources of Information to Ascertain Position

Answer 29

1. Vestibular System 2. Somatosensory System 3. Visual System

Question 30

The vestibular system

Answer 30

a sensory system in the inner ear that helps maintain balance, spatial orientation, and coordinates body movements, including eye movements, in response to head and body movements.

Question 31

Vertigo

Answer 31

The feeling of motion when one is stationary Signs & Symptoms: - Dizziness - Feeling like moving/spinning - Hearing loss - Balance Problem

Question 32

The somatosensory system

Answer 32

The somatosensory system is a vital part of the sensory nervous system that enables us to perceive and respond to physical sensations, including touch, pressure, temperature, pain, and awareness of body position and movement.

Question 33

The visual system

Answer 33

1. Light enters the Cornea 2. Travels through the Lens 3. Falls onto the Retina 4. Light Sensitive Cells convert the light energy to electrical impulses. 5. Brain interprets the electrical signals to images

Question 34

Light sensitive cells

Answer 34

Rods - Suited for low light levels - Unable to distinguish colors - Peripheral Vision Cones - Suited for daytime - Detail in vision - Color vision and sensitivity - Foveal Vision

Question 35

Day Vision

Answer 35

* A series of short regularly spaced Eye movements to search each 10-deg sector

Question 36

Fixation cycle

Answer 36

refers to a pilot's tendency to fixate on a single source of information, potentially leading to a narrow focus and missed cues Treatment: Systematically focusing on different segments of the sky for short intervals is a better technique than continuously sweeping the sky

Question 37

Night vision

Answer 37

Peripheral Vision - black/gray/white, moving objects, daylight and darkness. – Scanning of small sector of sky slowly and focusing perception from 5° to 10° off center of the object to be seen. * Cones – 5 to 10 minutes to adapt back to light * Rods – 30 minutes to adapt to the darkness Cones and rods affect vision

Question 38

Blindspot

Answer 38

– The area where the optic nerves leave the eyeball – There are no rods or cones

Question 39

Color blindness

Answer 39

The decreased ability to perceive differences in color

Question 40

Disqualifying Illness

Answer 40

– Heart attack, stroke, diabetes, kidney stones

Question 41

Debilitating Illness

Answer 41

– Migraines and Headaches – Viruses, flu, middle ear infection – Gastroenteritis – Cardiovascular diseases

Question 42

Stress Management

Answer 42

* Identifying hazardous attitudes * Learning to modify your behavior * Recognizing and coping with stress * Using all your resources * Being able to evaluate your performance