Chapter 4 - The atmosphere, oxygen and respiration Flashcards
What are the main components of the respiratory system? (3)
Trachea
Lungs
Pulmonary artery
What is the purpose of the trachea?
To carry air from the hose and mouth to the lungs.
What is the purpose of the lungs?
To absorb oxygen from inspired air and expel CO2 in expelled air.
What (related to oxygen content) remains constant at all altitudes at which common aircraft operate?
Volume percentage of the gasses in ambient air.
“Insufficient oxygen to support the metabolism of the tissues” describes what?
Hypoxia
Hypoxic hypoxia is caused by what?
What is the common reason?
Low saturation levels of oxygen in the blood.
Most common cuse is low partial pressure of atmospheric oxygen, associated with high altitude.
Anaemic hypoxia is caused by what?
What is the most common reason?
Caused by the ability of the blood to carry oxygen.
Likely reasons are carbon monoxide poisoning or low haemoglobin in the red blood cells.
Name symptoms of hypoxia (10)
tingling sensations in the extremities
Irritability / euphoria
Impaired judgement
Headache
Cyanosis
Increased breathing rate
impaired vision
drowsiness
slurred speech
loss of consciousness
What altitude are healthy individuals able to compensate for hypoxic hypoxia?
10,000 - 12,000ft
The three physiological thresholds for hypoxia are:
Reaction threshold:
Disturbance threshold:
Critical threshold:
What altitudes are linked to these?
Reaction threshold:
7000ft
Disturbance threshold:
10,000 - 12,000ft
Critical threshold:
22,000ft
At an altitude of 12,000ft what would start to be affected
Short term memory
Effective performance time is also known as?
Time of useful consciousness.
What is the time of useful consciousness for the following altitudes?
20,000ft
30,000ft
35,000ft
40,000ft
20,000ft - 30min
30,000ft - 1 - 2min
35,000ft - 30 - 90sec
40,000ft - 15 - 20sec
What are the factors that would increase/reduce the severity of hypoxia symptoms? (6)
Rapidness of onset
severity of conditions
level of physical activity
smoking
body weight
general health
________________ is the state of breathing faster and/or deeper than is necessary for the body’s current demand for oxygen.
Hyperventilation
What level determines the respiration rate?
CO2
When hyperventilating, the level of what gas falls significantly?
CO2
What can cause hyperventilation?
Deliberate
stress/anxiety
brain injury
strokes
Can be psychological or physiological
Diagnose this:
Rapid breathing rate
tingling or dizziness
hot/cold flushes
impaired performance
fainting
Hyperventilation
How to counteract hyperventilation?
Breathe slowly
Close nose or mouth
speak loudly
paper bag
What is the name for the capacity of the lungs that is never used?
Residual volume
What is the name for the capacity of the lungs that isn’t NORMALLY used?
Functional residual capacity
What would ‘tidal volume’ mean?
It can be ‘resting’ or ‘varying’
Breathing range.
Ranging from ‘resting’ to ‘vital capacity’
“Inspiration / expirator reserve volume” describes what part of the lung?
Top / bottom part of the wave. The amount of available space between normal breathing and “Vital capacity”
Which muscle draws air into the lungs?
diaphragm
Oxygen, nitrogen and other trace gasses are drawn into the lungs in a process called ________ ___________
External respiration
What is in the lungs and has thin membranes which allow gasses to diffuse into the blood stream?
Alveoli
The biproduct of cell metabolism is CO2. Blood passes by the cell membrane and exchanges the CO2 for O2. What is this process called?
Internal respiration
______ __________ is a measure (%) of the amount of oxygen in the haemoglobin.
What is a ‘normal’ reading for a healthy human?
Oxygen saturation 98%
What metric in the body holds steady until a cabin altitude of about 7000ft?
oxygen saturation level
What is the highest cabin altitude for CS-25 aircraft?
8000ft
If you experience a decompression, do not fly within __ _____.
Why?
24 hours
Decompression sickness precautions
