040 HPL
Human Performance and Limitations
Human Performance and Limitations
Kartei Details
| Karten | 25 |
|---|---|
| Sprache | English |
| Kategorie | Verkehrskunde |
| Stufe | Andere |
| Erstellt / Aktualisiert | 29.08.2022 / 29.11.2022 |
| Weblink |
https://card2brain.ch/box/20220829_040_hpl
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Calculate partial pressures at MSL, 3/4, 1/2, 1/4 atmospheric pressure.
What is the composition of blood?
- Cells: 45%
- Plasma: 55%
What is the lung circulatory system called?
Pulmonary: Blood flow between heart and lung
What is systemic circulation?
Blood flow from heart to rest of the body
What is cardiac circulation?
Blood flow within the heart
The rate and depth of breathing is controlled by receptor cells in the brain by measuring what?
They measure the pressure of CO2 in the blood. Normal is 40mmHG, by more than 70mmHG CO2: Atemreflex
What is external external respiration?
- Oxygen exchange from the lungs into the blood (hemoglobin/red blood cells)
- CO2 removed from the blood into the lung
What is internal respiration?
- O2 is burnt by the cells, CO2 and water are waste products
- CO2 turns to H2CO3 (Kohlensäure)
What are symptoms for hyperventilation?
- tingling in the hands
- dizziness
- light headedness
- shortness of breath
- muscle spasm in hands/ feet
- feeling cold/hot
What can prevent/treat hyperventilation?
- conscious control anxiety/pain/stress
- talking loud
- breathe into a bag
- calm down
- descent below 38.000ft
- breathe 100%O2
Why does the O2 partial pressure decrease in the body compared to the atmosphere?
During respiration the partial pressure of O2 is deceased to 100mmHg because the two gases CO2 and H2O increase in the gas mix
What is the threshold between the zone of full and incomplete compensation called and what is the oxygen saturation level?
Disturbance threshold (Störschwelle), 90% saturation.
At which oxygen saturation level is the critical threshold located?
65% saturation
List symptons of hypoxia:
- Euphoria
- Impaired judgement
- headache
- tingling in hands and feet
- hyperventilation
- muscular impairment
- sensory loss
- tunnel loss
- impairment of conciousness
- cyanosis
What is hypoxic hypoxia?
Hypoxic hypoxia: Results from insufficient partial pressure in inspired air (e.g. cabin pressures over 12‘000 ft, dysfunction of oxygen supply, decompression)
What is anaemic hypoxia?
Anaemic hypoxia: Reduction in oxygen carrying capacity (reduction of Hb), arterial oxygen pressure is normal, but total oxygen content of blood is reduced (carbon monoxide poising) (AVEX: hypaemic hypoxia)
What is ischemic hypoxia?
Ischemic hypoxia: Decreased/stopped blood circulation delivers less oxygen to target tissues (heart failure, shock, acceleration, pressure breathing).
What is histotoxic hypoxia?
Histotoxic hypoxia: Quantity of oxygen reaching the cells is normal, but the cells are unable to effectively use the oxygen due to disabled oxidative phosphorylation enzymes (CN- poising, alcohol)
State Boyle Mariotte‘s Gas Law based on volume and pressure.
The Volume of a gas is inversely proportional to its pressure, with temperature remaining constant.
With regards to Boyle Mariott, what happens to the volume at 34'000 ft when the gas is saturated?
Volume is 5 times greater (instead of 4)
List some airfilled organs which can be affected by Barotrauma?
- Ear (barotitis/aerotitis)
- Sinuses (barosinusitis/aerosinusitis)
- Teeth
- Gastrointestinal tract
Describe a barotrauma over the ear?
Pressure gradient over ear drum caused by blocked eustachian tube especially during descent (reason: lower pressure in middle ear narrows eustachian tube)
What prevention/therapy can applied when experiencing a barotrauma in the ear?
Non pressurised aircraft:
- stop descent, climb until pain decreases, descend again at slow rate
- swallow, chew (chewing gum), yaw
- wake up children (less swallowing during sleep)
- Valsalva manoeuvre
- nose spray / nose drops: not for flight crew members many contain sedative agents -> ask your AME!
What is another word for barotrauma in the sinuses?
Aerosinusitis, also called barosinusitis or sinus barotrauma.
What is the german word for the following?
- Frontal Sinuses
- Ethmoid Sinuses
- Maxillary Sinuses
- Stirnhöhlen
- Nasennebenhöhlen
- Kieferhöhlen
