Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

1. D1: Extreme environments > L3. Diving and hyperbaria > Flashcards

L3. Diving and hyperbaria Flashcards

1
Q

What are the primary environmental challenges of scuba diving?

A

Cold, pressure changes, gas toxicity, and nitrogen narcosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Who invented the first scuba diving system?

A

Jacques Cousteau

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the physiological significance of Boyle’s law in diving?

A

It explains the relationship between pressure and volume, crucial for understanding gas behavior under pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is immersion pulmonary oedema (IPO) and its primary cause?

A

A form of hydrostatic pulmonary oedema caused by immersion-induced pressure changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does nitrogen narcosis affect divers at depth?

A

It impairs judgment and motor skills due to the anesthetic properties of nitrogen at high partial pressures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the two types of oxygen toxicity in diving?

A

Pulmonary and central nervous system toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is decompression sickness (DCS), commonly known as ‘the bends’?

A

A condition caused by nitrogen bubbles forming in tissues during rapid decompression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the primary mechanism of bubble formation during decompression?

A

Bubbles form due to decreased pressure allowing dissolved gases to come out of solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does increased gas density at depth affect divers?

A

It increases work of breathing and exacerbates narcosis and oxygen toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the role of hyperbaric oxygen therapy in treating decompression illness?

A

It recompresses and crushes bubbles while providing 100% oxygen to aid nitrogen elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the physiological effects of a rapid ascent on lung tissue?

A

Rapid expansion of air can rupture alveoli, leading to arterial gas embolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the main gas mixtures used in technical diving?

A

Air, nitrox, normoxic trimix, hypoxic trimix, and heliox

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the function of closed-circuit rebreathers in diving?

A

To recycle exhaled gas by scrubbing CO2 and adding O2, reducing gas consumption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What factors increase the risk of IPO in divers?

A

Hyperhydration, exertion, negative-pressure breathing, and cold-induced vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the significance of the oxygen window in decompression?

A

It refers to the partial pressure difference between arterial and venous blood aiding nitrogen elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do exercise and diving interact to influence decompression risk?

A

Post-dive exercise reduces bubble formation; intense exercise can increase decompression risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the role of endothelial microparticles (EMPs) in diving physiology?

A

They are released by endothelial cells after pressure changes, playing a role in inflammation and coagulation

18
Q

What are the symptoms of nitrogen narcosis at depths of 50-60 meters?

A

Sleepiness, illusions, and impaired judgment

19
Q

How does hypoxic trimix help in deep technical dives?

A

By replacing nitrogen with helium to reduce narcosis and oxygen with helium to mitigate toxicity

20
Q

What are the long-term effects of repeated exposure to hyperbaric conditions?

A

Potential lung damage, neurological changes, and vascular issues

21
Q

What experiment demonstrated the relationship between nitrogen bubbles and decompression sickness?

A

Haldane’s goat experiments showed nitrogen bubbles in decompressed tissues

22
Q

What did Haldane’s studies reveal about decompression rates?

A

Slow decompression rates reduce bubble formation and decompression sickness risk

23
Q

What are the findings about pulmonary oedema in closed-circuit rebreather divers?

A

Negative-pressure breathing increases susceptibility to IPO in back-mounted counter-lung systems

24
Q

How does exercise before a dive affect venous gas emboli (VGE) formation?

A

Pre-dive exercise reduces VGE formation by improving endothelial function

25
Q

What mechanisms are proposed for bubble nucleation during decompression?

A

Micronuclei, crevice model, and tribonucleation are leading theories

26
Q

What factors were identified as major contributors to immersion pulmonary oedema (IPO)?

A

Hyperhydration, exertion, and cold-induced vasoconstriction were key factors

27
Q

What evidence links endothelial microparticles (EMPs) to decompression sickness?

A

EMPs activate inflammatory pathways and impair endothelial function

28
Q

What did MRI studies reveal about brain changes in divers after nitrogen narcosis?

A

Brain swelling and microbleeds were observed after narcosis episodes

29
Q

What role do calcium channel blockers play in mitigating IPO?

A

They reduce pulmonary vascular resistance and mitigate IPO

30
Q

What physiological evidence supports the oxygen window theory?

A

Lower venous partial pressures due to metabolic oxygen consumption support it

31
Q

How do variations in heart rate and bradycardia correlate with diving response?

A

Increased bradycardia and heart rate variability occur during cold immersion

32
Q

What long-term cardiovascular changes are seen in professional divers?

A

Increased arterial stiffness and ventricular hypertrophy were observed

33
Q

What findings were associated with nitric oxide and its role in oxygen toxicity?

A

Nitric oxide combines with ROS to form peroxynitrite, causing oxidative damage

34
Q

What did the Doppler studies reveal about VGE and ascent rate?

A

Higher ascent rates correlated with increased VGE formation

35
Q

What adaptations reduce nitrogen narcosis susceptibility in frequent divers?

A

Repeated exposure improves tolerance, possibly through synaptic plasticity

36
Q

How does gas density influence the work of breathing at depth?

A

Higher density increases resistance, making breathing harder

37
Q

What experimental findings link cold-induced vasoconstriction to IPO?

A

Peripheral vasoconstriction increased central blood volume and pulmonary pressures

38
Q

What role do RL shunts play in arterialising venous gas bubbles?

A

Shunts allow bubbles to bypass pulmonary filtration, leading to arterialisation

39
Q

What findings suggest genetic predispositions to diving illnesses?

A

Variants in EPAS1 and PFO presence increase risk of diving illnesses

40
Q

What experimental models have been used to study oxygen toxicity in the CNS?

A

Rodent models demonstrated seizures at high oxygen pressures

1. D1: Extreme environments (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions