Lesson 2 Flashcards
Internal (cellular) respiration converts inhaled Oxygen (O) into energy .
What gas is the product of this conversion?
Carbon Dioxide (CO2) is a product of this conversion
The mixture between CO2 and resident Water Vapor (H2O), produces what?
Carbonic Acid (H2CO3) making the blood acid
An excess of H2CO3 will cause excessive what?
An excess of H2CO3 will cause excessive acidity. ( pH < 7)
The body want’s to reset balanced values so it does what?
Breathing rate, blood pressure and heart rate, increase,to reset balanced values
Normal Breathing Rate =
12 to 20 bpm, averaging 16 bpm
What in the body senses the PH level and demands an increased rate of respiration
Central Chemoreceptors
What is ISA temperature
15°c
What is ISA pressure?
760 mm Hg / 29,92 PSI / 1013,2 hPa
What is ISA density?
1225 g/m3
What gasses are in the atmosphere?
21% oxygen
78% nitrogen
How can you describe the change in oxygen/nitrogen proportions in the atmosphere as you ascend.
Doesn’t change
Name the following:
Low arterial PO2 caused by
High altitude; alveolar hypoventilation;
decreased lung diffusion capacity;
abnormal ventilation-perfusion ratio
Hypoxic hypoxia
What is being described?
Decreased total amount of O2 bound to hemoglobin
Caused by:
Blood loss; anemia (low [Hb] or altered HbO2 binding); carbon monoxide poisoning
Anemic hypoxia
What factors determine the severity of hypoxia
Altitude
Time of exposure
Temperature
Physical Activity
Hemoglobin saturation at sea level is
97,5% saturated with oxygen
Hemoglobin saturation at 10,000ft is
87% saturated with oxygen
Hemoglobin saturation at 20,000ft is
65% saturated with oxygen
What are common causes of Anemic Hypoxia - inability of blood to carry oxygen
Medical condition
Carbon monoxide poisoning
Stagnant hypoxia is what kind of issue?
Circulatory
Histotoxic hypoxia is what kind of issue?
Cells are poisoned
(Drugs/Alcohol/Chemicals)
Initial hypoxia symptoms:
Tingling in hands and feet
Cyanosis - turning cyan
Increased rate of breathing
Headache, nausea, dizziness, sweating
Mood change (irritability / euphoria)
Further hypoxia symptoms:
Impaired vision
Impaired judgement
Muscular impairment
Memory impairment
Concentration impairment
Drowsiness
Slurred speech
Cyanosis is only ever a symptom of
Hypoxia
Minimum Safe Altitude , or Physiological Altitude is located at
10.000 feet
Night vision CAN be affected from which altitude
5000ft
40,000ft and above and what needs to happen to your oxygen supply
pressurised
When it comes to oxygen levels, describe an initial Complete Compensatory Stage including altitude
5,000 - 12,000ft
Body fully compensates the deficiency of oxygen by automatically changing the cardiac output and no Hypoxia related disturbances occur here.
When it comes to oxygen levels, describe Partial Compensatory Stage including altitude
12,000 - 20,000ft
a drastic increase in breathing is needed to maintain proper cardiovascular function and a degradation of the nervous functions start to take place
Oxygen will need pressurising over what altitude?
40,000ft
Over which altitude do you need 100% (not pressurised) oxygen
33,700ft
Hypoxia prevention
Ensure a serviceable supplementary supply of oxygen
Brief passengers on adequate use
Fly only if you are 100% fit and you are not taking any medication or drugs
Ensure that cabin heaters and ventilators are thoroughly checked and serviceable
Execute Checklists for Pressurization System Settings
Hypoxia countermeasures
Provide oxygen
Descend to Minimum Safe Altitude (MSA)
TUC means?
Time of useful consciousness
Time between oxygen being removed to not longer being useful
Effective performance time
EPT
TUC 20,000ft
30mins
TUC 30,000ft
1 -2 mins
TUC 35,000ft
30 - 90 seconds
TUC 40,000ft
15 - 20 seconds
The human body’s PH is in average (ish)
7.40 (7.35 to 7.45)
Define hyperventilation
An excessive rate and depth of breathing.
Breathing too much
If you experience hyperventilation the you will change what in the blood
Acid level which regulates the breathing
Hyperventilation symptoms
Increase rate and depth of breathing
Paleness of skin
Muscle spasms
Anxiety
Dizziness
Nausea
Numbness
Visual disturbance
A name for:
quick simultaneous movement of both eyes between two or more phases of fixation in the same direction
Saccade
What are the names for the muscles that move the eye balls?
The ciliary muscle plays a crucial role in accommodation, which allows us to focus on objects at varying distances.
Eye ball anatomy
look it up
Accommodation mean?
Cones
Colour
Clarity
Centre
Rods
Round the edges
Rhopsin
Peripheral vision
Central vision + peripheral vision =
visual field
Light adaptation Dark > light takes how long
10 seconds
Light adaptation Light > Dark takes how long
Cones - 7 mins
Rods - 30 mins (Rhodopsin)
Which part of the eye takes 30mins to adjust to the dark?
Rods (Rhodopsin)
Night vision is…
and effected by…
Affected above 5,000ft
Affecting factors
age
hypoxia
altitude
Smoking (20 cigarettes/day - night vision degradation of approximately 20%)
Alcohol
Lifestyle
Visual defects – colour vision deficiency
What type of vision runs out at 200ft / 60m
Binocular – stereoscopic
Myopic eye is known as ____ and corrected by
Short sighted
Diverging lens to correct
Hypermetropia is know as _____ sighted and corrected
Long sighted
Converging lens to correct
astigmatism is a wonky
cornea
Presbyopia is what?
Age related long sightedness
Cataracts are what?
Cloudy lens’
Glaucoma is what?
Pressure in the eye
Insidious onset
eye pressure test
drainage canal blocked
Which colour lens’ should you use?
Orange/yellow
What kinds of glasses are you allowed?
Contacts
Half moon / lookover
bifocal
What kinds of glasses are you not allowed?
bifocal contacts
varifocals
photo reactive
Describe:
Pinna
Flappy bit
Describe:
Auditory canal
tube you can stick a cotton bud into
Describe:
Tympanic membrane
Ear drum
Describe:
Ossicles
3 bones attached to the Typanic membrane
What are the names for the 3 bones that make up the Ossicles
Incus
Malleus
Stapes
Describe:
Vestibular system
Semi-circular canals
Describe:
Cochlea
Snail, connected to ossicles and full of liquid. Hairs on the inside
Describe:
Eustachian tube
Drain from middle ear (inside of tympanic membrane) to back of throat
What altitude do we pressurise a commercial aircraft to?
6000 - 8000ft
Providing what is not blocked, ear drum pressurisation shouldn’t be a problem.
Eustachian Tube
NIHL stands for
and what threshold are we looking at?
Noise induced hearing loss
90DB
Angular acceleration is sensed by the ____________ ______
Semicircular canals
Static head position + linear acceleration =
otolith organs
Without external cues, what is your circadian rhythm
25hours
How long is your circadian rhythm?
24hours
Body temperature is approx
37°c
What is a major controller of circadian rhythm
body temperature
Between roughly 0200 and 0600 is described as the
window of circadian low
In a time difference how long will it take someone to recover for time difference
1 day for each 90mins of time difference
