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Flashcards in Exam 1 Deck (66)
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1
Q

At what altitudes does pressure change most rapidly?

A

At LOWER altitudes! (SL to 10,000)

2
Q

At Sea Level on a standard day, mmHg = ____

A

760

3
Q

At 18,000’ on a standard day, mmHg = ____

A

380

4
Q

Above what altitude is supplemental oxygen needed to fully function?

A

10,000’

5
Q

Define Dalton’s Gas Law and it’s equation

A
  • Each component of a gas contributes to the total pressure.

- Partial Pressure = (total pressure) x (% gas)

6
Q

What is the partial pressure of Oxygen delivered by life support at the “service ceiling” (minimum) of the equipment?

A

104 (considered the partial oxygen minimum for life support)

7
Q

What is the formula to determine oxygen partial pressure?

A

Partial Pressure = (total pressure) x (% gas)

8
Q

What is the service ceiling for an oxygen system that delivers 40% to the human?

A
104 = (?) x (.40)
260 = ?
9
Q

What is the partial pressure available to a person breathing 28% oxygen at 26,000’ altitude?

A
PO2 = (269.8) x (.28)
PO2 = 75.544 mm Hg
10
Q

What minimal percentage of oxygen should an individual breathe to maintain peak performance at 24,000’ altitude?

A

104 = (294.4) x (?)
.35 = ?
(35%)

11
Q

What does Boyle’s Law discuss?

A

Gas when it is subjected to PRESSURE

- trapped gas, expansion and compression

12
Q

What does Charles’ Law discuss?

A

Gas when it is subjected to HEAT

13
Q

What does Henry’s Law discuss?

A

Gas when it is dissolved in solution (The Bends!)

14
Q

What does the Law of Gaseous Diffusion tell us?

A

Gases will diffuse from HIGH to LOW pressure naturally

15
Q

What are the 4 steps for oxygen processing in the human?

A
  1. Ventilation
  2. Diffusion
  3. Transporting
  4. Utilization
16
Q

Describe the Ventilation step of O2 Processing. What is the best respiratory rate?

A

Air is filtered, warmed, and humidified.

12 - 16 per minute

17
Q

What are the mechanics of Normal Breathing?

A
Inhalation = Active Effort
Exhalation = Passive
18
Q

What are the mechanics of Pressure Breathing?

A
Inhalation = Passive
Exhalation = Active Effort (purse your lips and blow out long and slow)
19
Q

Describe the Diffusion step of O2 Processing. What mm Hg will water vapor always equal?

A
  • O2 is diffused across the alveolar wall to the blood!
  • O2 and PRESSURE are inhaled (from the environment) and combined with WATER VAPOR and CO2 from within our body
  • Water Vapor = 47 mm Hg
20
Q

What is homeostasis?

A
  • The condition compatible with optimum cellular and bodily function
  • Body needs Nutrition, O2, and Rest for optimal homeostasis
21
Q

What is Hypoxia?

A

O2 deficiency in blood, body tissues and cells that causes impairment (feel normal but brain processes are slowed)

22
Q

What are the mechanics of Hypoxic Hypoxia? What are the most common causes?

A
  • FLOW of O2 to the LUNGS is interrupted

- Altitude, Drowning

23
Q

What are the mechanics of Histotoxic Hypoxia? What are the most common causes?

A
  • Normal METABOLIC ACTIVITY (Krebs Cycle) of O2 in the body/brain cells is interrupted
  • Alcohol, Cyanide
24
Q

What are the mechanics of Hypemic Hypoxia? What are the most common causes?

A
  • Ability of the blood cells to TRANSPORT O2 is interrupted

- Carbon Monoxide Poisoning, Smoke, Anemia

25
Q

What are the mechanics of Stagnant Hypoxia? What are the most common causes?

A
  • CIRCULATION of blood arriving at CELLS is interrupted

- G’s, Shock, Hyperventilation

26
Q

What is Deep Vein Thrombosis? What causes it?

A
  • Venous Flow
  • When you sit in one place for a long time without contracting your muscles, blood clots can form
  • When you get up and move, blood clots travel to lungs
27
Q

At what altitude does the temperature stabilize?

A

~35,500’+ = -55C

28
Q

Define effective performance time. What are the EPTs at FL180, FL250, and FL350?

A
  • The time from exposure to hypoxic conditions until an individual is no longer able to manage safe operations
    1. FL180 = 20-30 minutes
    2. FL250 = 3-5 minutes
    3. FL350 = 30-60 seconds
29
Q

How will a RAPID decompression affect EPTs?

A

It will decrease EPTs by 30-50%

30
Q

Describe hyperventilation

A
  • An abnormal increase in the rate and depth of breathing
  • Loss of CO2 exceeds the body’s production of CO2, leading to cerebral vasoconstriction and the brain going into a hypoxic state
31
Q

What are some symptoms of hyperventilation?

A

Gradual onset of:

  • Muscle spasms
  • Pale/clammy skin
32
Q

What are some symptoms of hypoxia?

A

Rapid onset of:

  • Flaccid muscles
  • Cyanosis
  • Difficulty interpreting info
  • Slow to respond to emergencies
33
Q

SCREAM checklist

A
Supply
Connections (5)
Regulator
Emergency Equipment
Adjustment (of mask)
Mask (condition)
34
Q

Describe the atmosphere. What are its functions? What are the components?

A

Functions as life support and protection, consists of pressure, water vapor, temperature…primary gases 78% Nitrogen 21% O2

35
Q

Describe some characteristics of Carbon Monoxide

A
  • 200-250 times more attractive to hemoglobin
  • Half-life of blood CO is 21.5 hours at rest
  • De-metabolizes in 5.25 hours when treated with 100% O2
  • De-metabolizes in 20-30 mins when treated with Hyperbaric Therapy
36
Q

Is it possible to have more than 1 type of hypoxia at once? Give an example.

A
Yes! Ex:
Rapid Decompression = Hypoxic
Cold Temp. = Stagnant
Medications = Histotoxic
Smoker = Hypemic
37
Q

How would you treat for hypoxia?

A
  • 100% O2
  • Breathe at a normal rate and depth
  • Descend below 10,000’
38
Q

When are Vasoconstrictors used to treat trapped gas?

A

In emergencies ONLY

39
Q

What would cause a delayed ear block?

A

Breathing 100% O2 after being in an environment breathing less than 100% (ex: being in the chamber)

40
Q

At what altitude will you encounter 1/2 the Earth’s atmosphere?

A

18,000’

41
Q

What is a Rapid Decompression?

A

Total loss of cabin pressure in less than .5 seconds (with a 10 psi pressure change)

42
Q

What is Evolved Gas referring to?

A

Gas forming were it did not exist before

43
Q

Explain how Henry’s Law applies to Decompression Sickness?

A

When the pressure drops, gas becomes supersaturated and bubbles out of solution - this causes expansion and inflammation of the cells

44
Q

What are the mechanics of Decompression Sickness?

A
  • O2 and CO2 get used up, but Nitrogen remains unused and gets absorbed by by the body and saturates the tissues
  • When pressure DECREASES around us, N becomes supersaturated and will bubble out of its solution, causing tissues inflammation (PAINFUL)
45
Q

How do we asses our risk (R value) for DCS?

A

Tissue Nitrogen partial pressure (P x N2 - pressure you’re at) and the Pressure surrounding the individual (PB - pressure you end up at)
R = P x N2/PB

46
Q

What are the 4 types of DCS?

A
  1. Bends
  2. Central Nervous System symptoms
  3. Skin symptoms
  4. Chokes
47
Q

What happens to someone experiencing the Bends?

A
  • N bubbles form in larger joints
  • Negative Pressure leads to bubble formation
  • Pain, can be alleviate with a return to pressure (pilots most likely to feel in the elbows/shoulders)
48
Q

What has happened to someone experiencing CNS symptom due to DCS?

A
  • N bubbles are in the brain and/or spinal cord
49
Q

What happens to someone experiencing Skin symptoms due to DCS?

A
  • N bubbles form under the skin
50
Q

What happens to someone experiencing the Chokes?

A
  • N bubbles form in the capillaries of lungs and prevent O2 transfer to blood (Stagnant Hypoxia)
51
Q

At what R value is saturation achieved? When do bubbles develop?

A
R = 1 (saturation - nothing happens)
R = 1.5 (bubbles)
52
Q

What are Oxygen Regulator Systems used for? What are the 3 different types?

A
  • Used to meter the flow of O2 to the user
    1. Continuous Flow
    2. Diluter Demand
    3. Pressure Demand
53
Q

Describe a Continuous Flow O2 Regulator System

A
  • PASSENGER Delivery System
  • Used from FL180 to FL250
  • Constant flow of 1L/10,000’
  • Inefficient
54
Q

Describe a Diluter Demand O2 Regulator System

A
  • AIRCREW Delivery System
  • Used up to FL350 ~operational ceiling~ (FL400 emergencies)
  • Provides mixture of 100% O2 and Ambient Air UPON DEMAND
55
Q

Describe a Pressure Demand O2 Regulator System

A
  • AIRCREW Delivery System
  • Used up to FL450 (FL500 emergencies)
  • Provides mixture of 100% O2, ambient air, AND supplemental pressure as altitude increases above 28,000’
  • Purpose: to raise partial pressure of O2 at lungs
  • Problems: Hyperventilation
56
Q

What are the FAA requirements for oxygen use in UNpressurized a/c? (91.211)

A
  • When cabin is between 12,500’ and 14,000’ for more than 30 minutes
  • If cabin exceeds 14,000’
  • PASSENGERS: If cabin exceeds 15,000’
57
Q

What are the FAA requirements for oxygen use in PRESSURIZED a/c? (91.211)

A
  • No Quick Don: With 2 pilots are at the controls, 1 must put on O2 at FL350
  • Quick Don: With 2 pilots at the controls, 1 pilot doesn’t have to don the mask until FL410. If 1 pilots leaves the controls above FL350 the other must don a mask
58
Q

What are the Connections referred to in the SCREAM checklist?

A
  1. Interfoam
  2. Nose
  3. Helmet
  4. Hose Connection
  5. ????
59
Q

Fick’s Law of Diffusion (equation)

A

Volume of a gas ~ (Area of Membrane) x (Diffusion Constant) x (Partial Pressure GRADIENT) / (Thickness of Membrane)

Vgas ~ (A)(D)(P1-P2)/T

60
Q

What 2 elements are inhaled from the environment during the Diffusion step of O2 processing?

A

O2 and PRESSURE

61
Q

What 2 elements are provided from within the body during the Diffusion step of O2 processing?

A

WATER VAPOR and CO2

62
Q

What % of O2 is required to be fully functioning at Sea Level? What about at 10,000’?

A
  • 21%

- 30%

63
Q

Durning a flight, who is most at risk to get Pyrolysis?

A

Flight Attendants because they are up and walking during the flight

64
Q

What is the half life of blood carbon monoxide at rest?

A

21.5 hours at rest

65
Q

How quickly will blood carbon monoxide de-metabolize when treated with 100% O2? What about hyperbaric therapy?

A
  • 5.25 hours

- 20 to 30 mins

66
Q

What is one of the most susceptible senses to O2 deprivation?

A

EYE SIGHT