Final: 15 Apr Extreme Conditions Atmospheric Pressure and Breathing Flashcards
What is atmospheric pressure a result of?
Gravity and the weight of the atmosphere
Atmospheric pressure is essentially the weight of the air above us, which varies with altitude.
What is the barometric pressure at sea level?
760 millimeters of mercury
What happens to barometric pressure as altitude increases?
It decreases
What is the highest altitude location on Earth?
Summit of Mount Everest at about 9000 meters
What is the barometric pressure at the summit of Mount Everest?
253 millimeters of mercury
What is the atmospheric oxygen concentration at high altitudes?
21%
Oxygen concentration remains constant at high altitudes, but lower pressure reduces the effective amount available.
What is the partial pressure of oxygen (PO2) at high altitudes like Everest?
43 millimeters of mercury
What effect does water vapor have on partial pressure calculations?
It adds a constant pressure of 47 millimeters of mercury
How long can most humans tolerate low inspired PO2 at high altitudes?
A couple of hours
What physiological response often occurs when ascending to high altitudes?
Hyperventilation
What role does EPO play in response to low PO2?
It increases red blood cell production
How does living at high altitude affect lung development?
Increased surface area for gas exchange due to more alveoli
What advantage do athletes from high-altitude regions have?
More lung surface area for oxygen exchange
What is the relationship between altitude and atmospheric pressure?
Lower altitude results in higher atmospheric pressure
What is the lowest altitude place on Earth?
Death Valley
What happens to pressure underwater as depth increases?
Pressure increases significantly due to water weight
What is the total environmental pressure at a depth of 500 feet?
16 times that at sea level
What is the partial pressure of oxygen at a depth of 500 feet?
1044 millimeters of mercury
What gas is primarily concerned with nitrogen toxicity during diving?
Nitrogen
What can happen if a diver surfaces too quickly from a deep dive?
Formation of nitrogen bubbles leading to decompression sickness
What are air emboli and why are they dangerous?
Bubbles of nitrogen in the circulatory system that can obstruct blood flow
Fill in the blank: At high altitudes, the body must adjust to _______ levels of oxygen.
Lower
True or False: The lungs are typically the limiting factor for athletic performance.
False
What can happen if air emboli occur in the left coronary artery?
It can be fatal.
What happens to nitrogen bubbles in the body during rapid decompression?
They can be incredibly dangerous and potentially lethal.
What is one method to prevent sudden decompression effects?
Come up gradually.
What is the purpose of hyperbaric chambers?
To simulate a high-pressure environment for gradual decompression.
What movie depicted the effects of rapid decompression?
Total Recall.
What is blood boiling in the context of decompression?
Transition of gases from liquid to gas phase due to pressure drop.
What is altitude sickness related to?
Genetic predisposition.
True or False: You should ascend rapidly from deep sea depths.
False.
What can happen when multiple air emboli come together?
They can form a larger embolus.
What is one way to eliminate nitrogen toxicity in diving?
Not including nitrogen in the inspired gas mixture.
What are the risks of using 100% oxygen in diving?
It can be explosive and lead to oxygen toxicity.
What is the typical pressure of a standard hyperbaric chamber?
About three times normal sea level pressure (up to 33 ATMs).
What are hyperbaric chambers used for besides decompression treatment?
Healing issues related to circulatory and immune systems.
What can excessive oxygen levels cause in the body?
Oxidative stress.
Fill in the blank: Oxygen is primarily carried in the blood by _______.
hemoglobin.
What is a common practice for divers to avoid decompression sickness?
Ascending slowly.
What can happen if too much CO2 is present in the blood?
It can be toxic and cause acidosis.
What is the typical oxygen percentage used in general anesthesia?
About 30%.
What is superoxide?
An O2 molecule with an extra electron.
What is the risk associated with having a hyperbaric chamber at high pressure?
It can be dangerous like a bomb.
What is a common use for mobile hyperbaric chambers?
To provide treatment at different hospitals.
What happens to the body if a diver ascends too quickly from deep water?
It can lead to nitrogen bubble formation in the tissues.
What is a potential benefit of living in high-pressure environments for divers?
It reduces the need for gradual acclimatization.
What is a common concentration of oxygen used in certain applications?
30%
This concentration is typically used to offset certain conditions.
What is superoxide?
An O2 molecule with an extra electron that is very reactive
The unpaired electron in superoxide is responsible for its reactivity.
What can excessive nitric oxide lead to?
Formation of dangerous compounds like peroxynitrite
Peroxynitrite can interact with DNA, causing mutations.
What is the formula for peroxynitrite?
O, N, O
Peroxynitrite is a highly reactive compound that can damage DNA.
What is hydrogen peroxide classified as?
A reactive oxygen species
It is used as an antiseptic and has specific roles in the immune response.
What enzymes regulate reactive oxygen species in the body?
- Superoxide dismutase
- Peroxidases
- Catalase
- Acetyl cysteines
These enzymes help manage the levels of reactive oxygen species to prevent damage.
What is N-acetyl cysteine used for?
To reduce liver damage from acetaminophen overdose
It acts by scavenging reactive oxygen species.
What is an iron lung?
A device used to ventilate patients with inadequate respiratory muscle function
It was commonly used for polio patients in the past.
How does an iron lung ventilate patients?
By creating a lower pressure environment to draw air into the lungs
This mimics natural breathing mechanics.
What is the difference between negative pressure and positive pressure ventilation?
- Negative pressure: air is drawn into the lungs
- Positive pressure: air is pushed into the lungs
Negative pressure is more akin to natural breathing.
Why is positive pressure ventilation considered abnormal?
It fills the inner alveoli first, pushing against others
This is contrary to the normal filling pattern of the lungs.
What are the advantages of using an iron lung over positive pressure ventilators?
- Closer to normal lung function
- Less trauma to the lungs
Iron lungs maintain a more natural breathing process.
What challenges are associated with using an iron lung?
Mobility issues and sourcing spare parts
The device is large and can be cumbersome.
What kind of lifestyle can a person in an iron lung maintain?
They can pursue education and work, as seen with a law degree obtained by a user
Some individuals have adapted to life in an iron lung despite its limitations.
True or False: Positive pressure ventilation is the standard method for all patients needing mechanical ventilation.
False
While common, it is not the only method and may not be the best for all patients.
