Final: 15 Apr Extreme Conditions Atmospheric Pressure and Breathing

Question 2

What is atmospheric pressure a result of?

Answer 2

Gravity and the weight of the atmosphere

Atmospheric pressure is essentially the weight of the air above us, which varies with altitude.

Question 3

What is the barometric pressure at sea level?

Answer 3

760 millimeters of mercury

Question 4

What happens to barometric pressure as altitude increases?

Answer 4

It decreases

Question 5

What is the highest altitude location on Earth?

Answer 5

Summit of Mount Everest at about 9000 meters

Question 6

What is the barometric pressure at the summit of Mount Everest?

Answer 6

253 millimeters of mercury

Question 7

What is the atmospheric oxygen concentration at high altitudes?

Answer 7

21%

Oxygen concentration remains constant at high altitudes, but lower pressure reduces the effective amount available.

Question 8

What is the partial pressure of oxygen (PO2) at high altitudes like Everest?

Answer 8

43 millimeters of mercury

Question 9

What effect does water vapor have on partial pressure calculations?

Answer 9

It adds a constant pressure of 47 millimeters of mercury

Question 10

How long can most humans tolerate low inspired PO2 at high altitudes?

Answer 10

A couple of hours

Question 11

What physiological response often occurs when ascending to high altitudes?

Answer 11

Hyperventilation

Question 12

What role does EPO play in response to low PO2?

Answer 12

It increases red blood cell production

Question 13

How does living at high altitude affect lung development?

Answer 13

Increased surface area for gas exchange due to more alveoli

Question 14

What advantage do athletes from high-altitude regions have?

Answer 14

More lung surface area for oxygen exchange

Question 15

What is the relationship between altitude and atmospheric pressure?

Answer 15

Lower altitude results in higher atmospheric pressure

Question 16

What is the lowest altitude place on Earth?

Answer 16

Death Valley

Question 17

What happens to pressure underwater as depth increases?

Answer 17

Pressure increases significantly due to water weight

Question 18

What is the total environmental pressure at a depth of 500 feet?

Answer 18

16 times that at sea level

Question 19

What is the partial pressure of oxygen at a depth of 500 feet?

Answer 19

1044 millimeters of mercury

Question 20

What gas is primarily concerned with nitrogen toxicity during diving?

Answer 20

Nitrogen

Question 21

What can happen if a diver surfaces too quickly from a deep dive?

Answer 21

Formation of nitrogen bubbles leading to decompression sickness

Question 22

What are air emboli and why are they dangerous?

Answer 22

Bubbles of nitrogen in the circulatory system that can obstruct blood flow

Question 23

Fill in the blank: At high altitudes, the body must adjust to _______ levels of oxygen.

Answer 23

Lower

Question 24

True or False: The lungs are typically the limiting factor for athletic performance.

Answer 24

False

Question 25

What can happen if air emboli occur in the left coronary artery?

Answer 25

It can be fatal.

Question 26

What happens to nitrogen bubbles in the body during rapid decompression?

Answer 26

They can be incredibly dangerous and potentially lethal.

Question 27

What is one method to prevent sudden decompression effects?

Answer 27

Come up gradually.

Question 28

What is the purpose of hyperbaric chambers?

Answer 28

To simulate a high-pressure environment for gradual decompression.

Question 29

What movie depicted the effects of rapid decompression?

Answer 29

Total Recall.

Question 30

What is blood boiling in the context of decompression?

Answer 30

Transition of gases from liquid to gas phase due to pressure drop.

Question 31

What is altitude sickness related to?

Answer 31

Genetic predisposition.

Question 32

True or False: You should ascend rapidly from deep sea depths.

Answer 32

False.

Question 33

What can happen when multiple air emboli come together?

Answer 33

They can form a larger embolus.

Question 34

What is one way to eliminate nitrogen toxicity in diving?

Answer 34

Not including nitrogen in the inspired gas mixture.

Question 35

What are the risks of using 100% oxygen in diving?

Answer 35

It can be explosive and lead to oxygen toxicity.

Question 36

What is the typical pressure of a standard hyperbaric chamber?

Answer 36

About three times normal sea level pressure (up to 33 ATMs).

Question 37

What are hyperbaric chambers used for besides decompression treatment?

Answer 37

Healing issues related to circulatory and immune systems.

Question 38

What can excessive oxygen levels cause in the body?

Answer 38

Oxidative stress.

Question 39

Fill in the blank: Oxygen is primarily carried in the blood by _______.

Answer 39

hemoglobin.

Question 40

What is a common practice for divers to avoid decompression sickness?

Answer 40

Ascending slowly.

Question 41

What can happen if too much CO2 is present in the blood?

Answer 41

It can be toxic and cause acidosis.

Question 42

What is the typical oxygen percentage used in general anesthesia?

Answer 42

About 30%.

Question 43

What is superoxide?

Answer 43

An O2 molecule with an extra electron.

Question 44

What is the risk associated with having a hyperbaric chamber at high pressure?

Answer 44

It can be dangerous like a bomb.

Question 45

What is a common use for mobile hyperbaric chambers?

Answer 45

To provide treatment at different hospitals.

Question 46

What happens to the body if a diver ascends too quickly from deep water?

Answer 46

It can lead to nitrogen bubble formation in the tissues.

Question 47

What is a potential benefit of living in high-pressure environments for divers?

Answer 47

It reduces the need for gradual acclimatization.

Question 48

What is a common concentration of oxygen used in certain applications?

Answer 48

30% ## Footnote This concentration is typically used to offset certain conditions.

Question 49

What is superoxide?

Answer 49

An O2 molecule with an extra electron that is very reactive ## Footnote The unpaired electron in superoxide is responsible for its reactivity.

Question 50

What can excessive nitric oxide lead to?

Answer 50

Formation of dangerous compounds like peroxynitrite ## Footnote Peroxynitrite can interact with DNA, causing mutations.

Question 51

What is the formula for peroxynitrite?

Answer 51

O, N, O ## Footnote Peroxynitrite is a highly reactive compound that can damage DNA.

Question 52

What is hydrogen peroxide classified as?

Answer 52

A reactive oxygen species ## Footnote It is used as an antiseptic and has specific roles in the immune response.

Question 53

What enzymes regulate reactive oxygen species in the body?

Answer 53

* Superoxide dismutase * Peroxidases * Catalase * Acetyl cysteines ## Footnote These enzymes help manage the levels of reactive oxygen species to prevent damage.

Question 54

What is N-acetyl cysteine used for?

Answer 54

To reduce liver damage from acetaminophen overdose ## Footnote It acts by scavenging reactive oxygen species.

Question 55

What is an iron lung?

Answer 55

A device used to ventilate patients with inadequate respiratory muscle function ## Footnote It was commonly used for polio patients in the past.

Question 56

How does an iron lung ventilate patients?

Answer 56

By creating a lower pressure environment to draw air into the lungs ## Footnote This mimics natural breathing mechanics.

Question 57

What is the difference between negative pressure and positive pressure ventilation?

Answer 57

* Negative pressure: air is drawn into the lungs * Positive pressure: air is pushed into the lungs ## Footnote Negative pressure is more akin to natural breathing.

Question 58

Why is positive pressure ventilation considered abnormal?

Answer 58

It fills the inner alveoli first, pushing against others ## Footnote This is contrary to the normal filling pattern of the lungs.

Question 59

What are the advantages of using an iron lung over positive pressure ventilators?

Answer 59

* Closer to normal lung function * Less trauma to the lungs ## Footnote Iron lungs maintain a more natural breathing process.

Question 60

What challenges are associated with using an iron lung?

Answer 60

Mobility issues and sourcing spare parts ## Footnote The device is large and can be cumbersome.

Question 61

What kind of lifestyle can a person in an iron lung maintain?

Answer 61

They can pursue education and work, as seen with a law degree obtained by a user ## Footnote Some individuals have adapted to life in an iron lung despite its limitations.

Question 62

True or False: Positive pressure ventilation is the standard method for all patients needing mechanical ventilation.

Answer 62

False ## Footnote While common, it is not the only method and may not be the best for all patients.