Notes: Maintaining Life

• Maintaining Boundaries• Movement• Responsiveness• Digestion • Metabolism• Excretion• Reproduction• GrowthHow do systems work

together to promote these functions?

Notes: Maintaining Life

• Maintaining Boundaries• Movement• Responsiveness• Digestion • Metabolism• Excretion• Reproduction• GrowthHow do systems work

together to promote these functions?

Our First Example: The Death ZoneWhat is hypoxia? What are the symptoms?

How can this been seen as a positive feedbackmechanism?

How does oxygen debt affect the brain?What makes Everest “Everest”?Why does your probability to make mental

errorsincrease?Why does heart rate increase at altitude? What is

this called?What are the affects of decreased oxygen to the

brain? Does this cause brain damage? How is this studied?

What are some symptoms of oxygen deprivation? What is Acute Mountain Sickness? What are its

initial symptoms? What happens as it progresses?

Where else might this happen?Why do climbers return to base camp before

ascending further?What is high altitude pulmonary edema (H.A.P.E.)?

How does it cause death?Why aren’t bodies removed from Everest?Why do bones remain after other tissues are

eliminated?Why is the area above 27,000 ft. called the “death

zone”?What happens when your resting heart rate matches

your maximum heart rate?What are some specific dangers/emergency

situations that may occur under these circumstances?

Will David ever reach the summit of Everest Again?

Gamow Bag

Not so elite

Next…

Survival Needs

1. Constant atmospheric pressure

2. Homeostasis

What went wrong? How does diving work?

Scuba

Jacques Cousteau

Boyle’s Law

Boyle’s Law: The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system.

Boyle's law describes how the pressure of a gas tends to decrease as the volume of a gas increases.

The pressure of the gas also increases as the volume decreases

Rebreather

Nitrogen in the blood

The bends

Nitrogen Narcosis “Narcing”• Nitrogen narcosis or inert gas narcosis is a reversible

alteration in consciousness producing a state similar to alcohol intoxication in Scuba divers at depths beyond 30m. Jacques Cousteau famously described it as the "rapture of the deep". Its precise mechanism is not well understood, but it appears to be a direct effect of high nitrogen pressure on nerve transmission. While it was first observed with nitrogen (in air), other gases including argon and hydrogen also cause very similar effects under high enough pressure. Xenon is actually a usable anaesthetic at atmospheric pressure, though it is too expensive to be used in practice.

• The onset is hard to recognize, its severity is unpredictable, and it can kill, from its own toxic effect or due to the resulting illogical behavior. However the cure for nitrogen narcosis is a simple one, as effects disappear upon ascending to shallower waters

CO2 retention

• CO2 retention is a pathophysiological process in which too little carbon dioxide is removed from the blood by the lungs. The end result is hypercarbia, an elevated level of carbon dioxide dissolved in the bloodstream. Various diseases may lead to this state; disturbed gas exchange may lead to impaired excretion of the gas. In addition, breathing air with a high carbon dioxide concentration may also lead to hypercarbia.

• The principal result of the increased amount of dissolved CO2 is acidosis (respiratory acidosis when caused by impaired lung function); other effects include tachycardia (rapid heart rate) seizures, coma, respiratory arrest and death.

In diving

• CO2 retention with its attendant dangers of death from convulsions and hypoxia (low oxygen level) is primarily of concern to the scuba diver due to "skip breathing". Other sources of CO2 retention are breath-hold diving, breathing in a sealed environment, faulty regulator, exercise at extreme depth and using contaminated air.

• Symptoms include rapid respiration in 4-6%, rapid pulse rate, shortness of breath in 7-10% and convulsions and unconsciousness in 11-20%.

• The CO2 level in the blood is unchanged by the ambient pressure (i.e., the depth) per se, since the partial pressure of carbon dioxide in a scuba diver's blood is a function only of metabolism and the rate and depth of breathing - the same factors that determine blood CO2 concentration on land.

While Diving…

All of the CO2 developed during breathing underwater is exhaled in the bubbles from scuba apparatus and does not increase with depth as do other gases, such as nitrogen, oxygen, carbon monoxide and hydrocarbons. Abnormal carbon dioxide accumulation in the blood can occur from too high a level of metabolism (such as from exercise at depth) and/or inadequate breathing (usually not breathing deep enough or skip breathing). The medical term for high carbon dioxide in the blood is hypercapnia; when the level is high enough it can cause "CO2 toxicity," which can lead to shortness of breath, headache, confusion and drowning (depending on severity).

Elevated CO2 levels

• Elevated CO2 levels play a significant role in oxygen toxicity and in nitrogen narcosis. The acceptable CO2 level for diving operations is 1.5% surface equivalent (10.5 mmHg); the acceptable level for hyperbaric oxygen therapy operations is one that allows a vent schedule of 4scfm/person displacement

Rebreathers

• With the increased usage of rebreather diving, mainly by the military-but recently by more and more civilian divers, there is the possibility of hypercarbia (high CO2 levels), among other medical considerations.

Further…

• What is the danger of breathing so rapid and shallow at these depths/altitudes?

• Why was Don Shirley so interested in mimicking Dave Shaw’s breathing?

• What does he mean when he says “I actually died with Dave”.

• Why was the experiment with David Carter similar?

• How are these experiences the same, how are they different?

Homeostasis

1. Negative Feedback Mechanisms2. Positive Feedback Mechanisms

Feedback loops

Negative feedback loop: monitors the environment, responds to changes, then shuts itself off. (self –regulated)

-constantly monitors

-responds to everyday changes

Positive feedback loop: responds to traumatic, potentially catastrophic events.

-cascade effect

-does not shut itself off

NFM: Body Temp

Hypothalamus: Temperature Regulation Center

NFM: Body Temp

Negative Feedback Mechanism

Ex: Blood Sugar Regulation

Negative Feedback Mechanism: Blood sugar regulation

Negative Feedback Mechanism

Positive Feedback Mechanism: Bleeding

Ex: Blood Clotting

Positive Feedback mechanism: Childbirth

How breathing Works: Breathing as a feedback

mechanism

How is breathing controlled?

http://www.nhlbi.nih.gov/health/health-topics/topics/hlw/controls

Shark drawings

Cuts, Cavities, and Directions

1. Intro to Anatomical/Directional Terminology2. Creepy Guy Lab3. Read pp. 14-21 and answer questions 1-18

Stayin’ Alive

Survival Need: Constant and moderate atmospheric

pressureHow does the body stay alive in

normal at situations?How does it react when pushed to and

beyond extremes?

Notes: Maintaining Life

• Maintaining Boundaries• Movement• Responsiveness• Digestion • Metabolism• Excretion• Reproduction• GrowthHow do systems work

together to promote these functions?

Notes: Maintaining Life

• Maintaining Boundaries• Movement• Responsiveness• Digestion • Metabolism• Excretion• Reproduction• GrowthHow do systems work

together to promote these functions?

Our First Example: The Death ZoneWhat is hypoxia? What are the symptoms?

How can this been seen as a positive feedbackmechanism?

How does oxygen debt affect the brain?What makes Everest “Everest”?Why does your probability to make mental

errorsincrease?Why does heart rate increase at altitude? What is

this called?What are the affects of decreased oxygen to the

brain? Does this cause brain damage? How is this studied?

What are some symptoms of oxygen deprivation? What is Acute Mountain Sickness? What are its

initial symptoms? What happens as it progresses?

Where else might this happen?Why do climbers return to base camp before

ascending further?What is high altitude pulmonary edema (H.A.P.E.)?

How does it cause death?Why aren’t bodies removed from Everest?Why do bones remain after other tissues are

eliminated?Why is the area above 27,000 ft. called the “death

zone”?What happens when your resting heart rate matches

your maximum heart rate?What are some specific dangers/emergency

situations that may occur under these circumstances?

Will David ever reach the summit of Everest Again?

Next…

What went wrong? How does diving work?

Scuba

Jacques Cousteau

Rebreather

Boyle’s Law

Deep Trouble• What is the name of the cave,

and where is it?• Who is Dave Shaw and what

happened to him?• How (Be Specific)?• What are the dangers of deep-

water diving?• Why is it especially dangerous to

combine extreme depth with demanding work?

• What was not anticipated before the dive?

• How did this affect the dive?• What is the danger of having too

much nitrogen in the blood? How do the body’s feedback mechanisms work this out?

• What is the danger of having too much helium in the blood? How do the body’s feedback mechanisms work this out?

• What are decompression stops?• What are recompression

chambers (hyperbaric)? How do they work?

Further…

• What is the danger of breathing so rapid and shallow at these depths/altitudes?

• Why was Don Shirley so interested in mimicking Dave Shaw’s breathing?

• What does he mean when he says “I actually died with Dave”.

• Why was the experiment with David Carter similar?

• How are these experiences the same, how are they different?

Nitrogen Narcosis “Narcing”• Nitrogen narcosis or inert gas narcosis is a reversible

alteration in consciousness producing a state similar to alcohol intoxication in Scuba divers at depths beyond 30m. Jacques Cousteau famously described it as the "rapture of the deep". Its precise mechanism is not well understood, but it appears to be a direct effect of high nitrogen pressure on nerve transmission. While it was first observed with nitrogen (in air), other gases including argon and hydrogen also cause very similar effects under high enough pressure. Xenon is actually a usable anaesthetic at atmospheric pressure, though it is too expensive to be used in practice.

• The onset is hard to recognize, its severity is unpredictable, and it can kill, from its own toxic effect or due to the resulting illogical behavior. However the cure for nitrogen narcosis is a simple one, as effects disappear upon ascending to shallower waters

CO2 retention

• CO2 retention is a pathophysiological process in which too little carbon dioxide is removed from the blood by the lungs. The end result is hypercarbia, an elevated level of carbon dioxide dissolved in the bloodstream. Various diseases may lead to this state; disturbed gas exchange may lead to impaired excretion of the gas. In addition, breathing air with a high carbon dioxide concentration may also lead to hypercarbia.

• The principal result of the increased amount of dissolved CO2 is acidosis (respiratory acidosis when caused by impaired lung function); other effects include tachycardia (rapid heart rate) seizures, coma, respiratory arrest and death.

In diving

• CO2 retention with its attendant dangers of death from convulsions and hypoxia (low oxygen level) is primarily of concern to the scuba diver due to "skip breathing". Other sources of CO2 retention are breath-hold diving, breathing in a sealed environment, faulty regulator, exercise at extreme depth and using contaminated air.

• Symptoms include rapid respiration in 4-6%, rapid pulse rate, shortness of breath in 7-10% and convulsions and unconsciousness in 11-20%.

• The CO2 level in the blood is unchanged by the ambient pressure (i.e., the depth) per se, since the partial pressure of carbon dioxide in a scuba diver's blood is a function only of metabolism and the rate and depth of breathing - the same factors that determine blood CO2 concentration on land.

While Diving…

All of the CO2 developed during breathing underwater is exhaled in the bubbles from scuba apparatus and does not increase with depth as do other gases, such as nitrogen, oxygen, carbon monoxide and hydrocarbons. Abnormal carbon dioxide accumulation in the blood can occur from too high a level of metabolism (such as from exercise at depth) and/or inadequate breathing (usually not breathing deep enough or skip breathing). The medical term for high carbon dioxide in the blood is hypercapnia; when the level is high enough it can cause "CO2 toxicity," which can lead to shortness of breath, headache, confusion and drowning (depending on severity).

Elevated CO2 levels

• Elevated CO2 levels play a significant role in oxygen toxicity and in nitrogen narcosis. The acceptable CO2 level for diving operations is 1.5% surface equivalent (10.5 mmHg); the acceptable level for hyperbaric oxygen therapy operations is one that allows a vent schedule of 4scfm/person displacement

Rebreathers

• With the increased usage of rebreather diving, mainly by the military-but recently by more and more civilian divers, there is the possibility of hypercarbia (high CO2 levels), among other medical considerations.

Raising the Dead

Positive and negative feedback mechanisms

Raising the DeadGood idea?Anatomical Planes

and Terminology

Sound Familiar?

• Signs and symptoms that need to be observed are hyperventilation, shortness of breath and tachycardia (rapid heart beat), headache and excessive sweating, mental impairment and finally, unconsciousness.

What killed Dave Shaw?

According to Nuno Gomes, who understands why Shaw had trouble reacting to a body that was suddenly floating instead of anchored. “You don’t think of a new plan while you’re down there. It doesn’t work. Your mind is clouded.

What negative feedback mechanisms was enacted that

day?• Shaw passed out due to toxic levels

of CO2

Response:

“Today, extreme divers are far exceeding any reasonable physiology capabilities”

Is this type if diving responsible?

Is any of this a good idea?

What are some other dangers that divers face?

Hyperbaric medicine

Hyperbaric medicine is a corollary field associated with diving, since recompression in a hyperbaric chamber is used as a treatment for two of the most significant diving related illnesses, decompression illness and arterial gas embolism

Happy Wednesday Quiz

1. What is a negative feedback mechanism? Please give an example.

2. What is a positive feedback mechanism? Please give an example.

Is any of this a good idea?

Reminder: Human Hibernation?

Read pp. 8-13 Then Read Article: “Suspended Animation”

Homework: Answer the question: Is induced hibernation a useful technology/process to pursue?

OrWhat is the future of induced hibernation?

Homeostatic Control Mechanisms

Negative feedback mechanismsPositive feedback mechanisms

Homeostatic Control Mechanisms

Negative Feedback mechanism

Homeostatic Control Mechanisms

Positive Feedback mechanism

Raising the Dead

Positive and negative feedback mechanisms

Raising the DeadGood idea?Anatomical Planes

and Terminology

Deep Trouble• What is the name of the cave,

and where is it?• Who is Dave Shaw and what

happened to him?• How (Be Specific)?• What are the dangers of deep-

water diving?• Why is it especially dangerous to

combine extreme depth with demanding work?

• What was not anticipated before the dive?

• How did this affect the dive?• What is the danger of having too

much nitrogen in the blood? How do the body’s feedback mechanisms work this out?

• What is the danger of having too much helium in the blood? How do the body’s feedback mechanisms work this out?

• What are decompression stops?• What are recompression

chambers (hyperbaric)? How do they work?

Further…

• What is the danger of breathing so rapid and shallow at these depths/altitudes?

• Why was Don Shirley so interested in mimicking Dave Shaw’s breathing?

• What does he mean when he says “I actually died with Dave”.

• Why was the experiment with David Carter similar?

• How are these experiences the same, how are they different?

• Could Dave Shaw have lived if he had people there?

• Why couldn’t anybody help him?

• They are both practical examples of gas laws studied in chemistry.

Nitrogen Narcosis “Narcing”• Nitrogen narcosis or inert gas narcosis is a reversible

alteration in consciousness producing a state similar to alcohol intoxication in Scuba divers at depths beyond 30m. Jacques Cousteau famously described it as the "rapture of the deep". Its precise mechanism is not well understood, but it appears to be a direct effect of high nitrogen pressure on nerve transmission. While it was first observed with nitrogen (in air), other gases including argon and hydrogen also cause very similar effects under high enough pressure. Xenon is actually a usable anaesthetic at atmospheric pressure, though it is too expensive to be used in practice.

• The onset is hard to recognize, its severity is unpredictable, and it can kill, from its own toxic effect or due to the resulting illogical behavior. However the cure for nitrogen narcosis is a simple one, as effects disappear upon ascending to shallower waters

CO2 retention

• CO2 retention is a pathophysiological process in which too little carbon dioxide is removed from the blood by the lungs. The end result is hypercarbia, an elevated level of carbon dioxide dissolved in the bloodstream. Various diseases may lead to this state; disturbed gas exchange may lead to impaired excretion of the gas. In addition, breathing air with a high carbon dioxide concentration may also lead to hypercarbia.

• The principal result of the increased amount of dissolved CO2 is acidosis (respiratory acidosis when caused by impaired lung function); other effects include tachycardia (rapid heart rate) seizures, coma, respiratory arrest and death.

In diving

• CO2 retention with its attendant dangers of death from convulsions and hypoxia (low oxygen level) is primarily of concern to the scuba diver due to "skip breathing". Other sources of CO2 retention are breath-hold diving, breathing in a sealed environment, faulty regulator, exercise at extreme depth and using contaminated air.

• Symptoms include rapid respiration in 4-6%, rapid pulse rate, shortness of breath in 7-10% and convulsions and unconsciousness in 11-20%.

• The CO2 level in the blood is unchanged by the ambient pressure (i.e., the depth) per se, since the partial pressure of carbon dioxide in a scuba diver's blood is a function only of metabolism and the rate and depth of breathing - the same factors that determine blood CO2 concentration on land.

While Diving…

All of the CO2 developed during breathing underwater is exhaled in the bubbles from scuba apparatus and does not increase with depth as do other gases, such as nitrogen, oxygen, carbon monoxide and hydrocarbons. Abnormal carbon dioxide accumulation in the blood can occur from too high a level of metabolism (such as from exercise at depth) and/or inadequate breathing (usually not breathing deep enough or skip breathing). The medical term for high carbon dioxide in the blood is hypercapnia; when the level is high enough it can cause "CO2 toxicity," which can lead to shortness of breath, headache, confusion and drowning (depending on severity).

Elevated CO2 levels

• Elevated CO2 levels play a significant role in oxygen toxicity and in nitrogen narcosis. The acceptable CO2 level for diving operations is 1.5% surface equivalent (10.5 mmHg); the acceptable level for hyperbaric oxygen therapy operations is one that allows a vent schedule of 4scfm/person displacement

Rebreathers

• With the increased usage of rebreather diving, mainly by the military-but recently by more and more civilian divers, there is the possibility of hypercarbia (high CO2 levels), among other medical considerations.

Sound Familiar?

• Signs and symptoms that need to be observed are hyperventilation, shortness of breath and tachycardia (rapid heart beat), headache and excessive sweating, mental impairment and finally, unconsciousness.

What killed Dave Shaw?

According to Nuno Gomes, who understands why Shaw had trouble reacting to a body that was suddenly floating instead of anchored. “You don’t think of a new plan while you’re down there. It doesn’t work. Your mind is clouded.

What negative feedback mechanisms was enacted that

day?• Shaw passed out due to toxic levels

of CO2

Response:

“Today, extreme divers are far exceeding any reasonable physiology capabilities”

Is this type if diving responsible?

Is any of this a good idea?

What are some other dangers that divers face?

Hyperbaric medicine

Hyperbaric medicine is a corollary field associated with diving, since recompression in a hyperbaric chamber is used as a treatment for two of the most significant diving related illnesses, decompression illness and arterial gas embolism

Happy Wednesday Quiz

1. What is a negative feedback mechanism? Please give an example.

2. What is a positive feedback mechanism? Please give an example.

Human Hibernation Assignment

Read pp. 8-13 Then Read Article: “Suspended Animation”Homework: Answer the question is a single page-single

spaced essay (or 2 pages double spaced) Is induced hibernation a useful technology/process to pursue? OrWhat is the future of induced hibernation?

Due By Tuesday

Think: Could induced hibernation change the way

we save lives involving traumatic injuries?Ho could induced hibernation advance space

travel and colonization?

Our First Example: The Death ZoneWhat is hypoxia? What are the symptoms?

How can this been seen as a positive feedbackmechanism?

How does oxygen debt affect the brain?What makes Everest “Everest”?Why does your probability to make mental

errorsincrease?Why does heart rate increase at altitude? What is

this called?What are the affects of decreased oxygen to the

brain? Does this cause brain damage? How is this studied?

What are some symptoms of oxygen deprivation? What is Acute Mountain Sickness? What are its

initial symptoms? What happens as it progresses?

Where else might this happen?Why do climbers return to base camp before

ascending further?What is high altitude pulmonary edema (H.A.P.E.)?

How does it cause death?Why aren’t bodies removed from Everest?Why do bones remain after other tissues are

eliminated?Why is the area above 27,000 ft. called the “death

zone”?What happens when your resting heart rate matches

your maximum heart rate?What are some specific dangers/emergency

situations that may occur under these circumstances?

Will David ever reach the summit of Everest Again?

Are there any other examples that you can think of that highlight the physiological effects of the body’s inability to acclimatize to extreme climates?

Into Thin Air Jon Krakauer, an experienced

climber and outdoor journalist, was sent to climb Mt. Everest in Nepal in the spring of 1996.   Late at night on the evening of May 9, 1996, after weeks of grueling climbing, acclimatization to low oxygen at high altitudes, illness, blinding snow, bitter cold, and hurricane force winds, the clients of several climbing organizations from the US, New Zealand, South Africa, and Taiwan reached an altitude of 26,000 feet before making the final ascent to the peak.

Jon KrakauerKrakauer and his companions led by

professional climbing guides and experienced Sherpas left camp at midnight on May 10th on what developed into a perfect morning for reaching the summit. By 4:00 pm, two full hours beyond the discussed but not enforced mandatory turn around time, the weather conditions change rapidly from tranquil to blizzard in a matter of minutes. Winds are blowing with gale-force strength and as night falls the temperature with wind chill is more than 100 degrees below zero. With no shelter and a shortage of oxygen canisters, 30 individuals are exposed and freezing above 26,000 feet on the barren, icy slopes of Everest. Krakauer loses several climbing partners and climbers from other groups, and two experienced expedition-leading guides.

The Climb

Written the same day on Everest, but told from a different perspective.

Some believe

That although “Into Thin Air” was an international best-seller and Jon Krakauer is an accomplished writer and semi-professional climber, his views were distorted during the expedition and led to inaccurate accounts. Whereas Annatoli Boukreev is a more accomplished guide and his account, based on physiology alone,

may be more accurate.

Who to believe?

Is it possible for some to be more physiologically disposed

to these extremes?

Fall 2010

quiz

1. Define negative feedback mechanism and give and example.

2. Define positive feedback mechanism and give an example.

Raising the Dead

Positive and negative feedback mechanisms

Raising the DeadGood idea?Anatomical Planes

and Terminology

Raising the Dead

Deep Trouble• What is the name of the cave,

and where is it?• Who is Dave Shaw and what

happened to him?• How (Be Specific)?• What are the dangers of deep-

water diving?• Why is it especially dangerous to

combine extreme depth with demanding work?

• What was not anticipated before the dive?

• How did this affect the dive?• What is the danger of having too

much nitrogen in the blood? How do the body’s feedback mechanisms work this out?

• What is the danger of having too much helium in the blood? How do the body’s feedback mechanisms work this out?

• What are decompression stops?• What are recompression

chambers (hyperbaric)? How do they work?

Is any of this a good idea?

Next class: Homeostasis and homeostatic control mechanisms.

Homework: Find and UNDERSTAND an example of either a positive or negative feedback mechanism. In the body or elsewhere…(20 points)

Further…

• What is the danger of breathing so rapid and shallow at these depths/altitudes?

• Why was Don Shirley so interested in mimicking Dave Shaw’s breathing?

• What does he mean when he says “I actually died with Dave”.

• Why was the experiment with David Carter similar?

• How are these experiences the same, how are they different?

Raising the Dead

Positive and negative feedback mechanisms

Raising the DeadGood idea?Anatomical Planes

and Terminology

• Could Dave Shaw have lived if he had people there?

• Why couldn’t anybody help him?

• They are both practical examples of gas laws studied in chemistry.

Nitrogen Narcosis “Narcing”• Nitrogen narcosis or inert gas narcosis is a reversible

alteration in consciousness producing a state similar to alcohol intoxication in Scuba divers at depths beyond 30m. Jacques Cousteau famously described it as the "rapture of the deep". Its precise mechanism is not well understood, but it appears to be a direct effect of high nitrogen pressure on nerve transmission. While it was first observed with nitrogen (in air), other gases including argon and hydrogen also cause very similar effects under high enough pressure. Xenon is actually a usable anaesthetic at atmospheric pressure, though it is too expensive to be used in practice.

• The onset is hard to recognize, its severity is unpredictable, and it can kill, from its own toxic effect or due to the resulting illogical behavior. However the cure for nitrogen narcosis is a simple one, as effects disappear upon ascending to shallower waters

CO2 retention

• CO2 retention is a pathophysiological process in which too little carbon dioxide is removed from the blood by the lungs. The end result is hypercarbia, an elevated level of carbon dioxide dissolved in the bloodstream. Various diseases may lead to this state; disturbed gas exchange may lead to impaired excretion of the gas. In addition, breathing air with a high carbon dioxide concentration may also lead to hypercarbia.

• The principal result of the increased amount of dissolved CO2 is acidosis (respiratory acidosis when caused by impaired lung function); other effects include tachycardia (rapid heart rate) seizures, coma, respiratory arrest and death.

In diving

• CO2 retention with its attendant dangers of death from convulsions and hypoxia (low oxygen level) is primarily of concern to the scuba diver due to "skip breathing". Other sources of CO2 retention are breath-hold diving, breathing in a sealed environment, faulty regulator, exercise at extreme depth and using contaminated air.

• Symptoms include rapid respiration in 4-6%, rapid pulse rate, shortness of breath in 7-10% and convulsions and unconsciousness in 11-20%.

• The CO2 level in the blood is unchanged by the ambient pressure (i.e., the depth) per se, since the partial pressure of carbon dioxide in a scuba diver's blood is a function only of metabolism and the rate and depth of breathing - the same factors that determine blood CO2 concentration on land.

While Diving…

All of the CO2 developed during breathing underwater is exhaled in the bubbles from scuba apparatus and does not increase with depth as do other gases, such as nitrogen, oxygen, carbon monoxide and hydrocarbons. Abnormal carbon dioxide accumulation in the blood can occur from too high a level of metabolism (such as from exercise at depth) and/or inadequate breathing (usually not breathing deep enough or skip breathing). The medical term for high carbon dioxide in the blood is hypercapnia; when the level is high enough it can cause "CO2 toxicity," which can lead to shortness of breath, headache, confusion and drowning (depending on severity).

Elevated CO2 levels

• Elevated CO2 levels play a significant role in oxygen toxicity and in nitrogen narcosis. The acceptable CO2 level for diving operations is 1.5% surface equivalent (10.5 mmHg); the acceptable level for hyperbaric oxygen therapy operations is one that allows a vent schedule of 4scfm/person displacement

Rebreathers

• With the increased usage of rebreather diving, mainly by the military-but recently by more and more civilian divers, there is the possibility of hypercarbia (high CO2 levels), among other medical considerations.

Sound Familiar?

• Signs and symptoms that need to be observed are hyperventilation, shortness of breath and tachycardia (rapid heart beat), headache and excessive sweating, mental impairment and finally, unconsciousness.

What killed Dave Shaw?

According to Nuno Gomes, who understands why Shaw had trouble reacting to a body that was suddenly floating instead of anchored. “You don’t think of a new plan while you’re down there. It doesn’t work. Your mind is clouded.

What negative feedback mechanisms was enacted that

day?• Shaw passed out due to toxic levels

of CO2

Response:

“Today, extreme divers are far exceeding any reasonable physiology capabilities”

Is this type if diving responsible?

What are some other dangers that divers face?

Hyperbaric medicine

Hyperbaric medicine is a corollary field associated with diving, since recompression in a hyperbaric chamber is used as a treatment for two of the most significant diving related illnesses, decompression illness and arterial gas embolism

Are there any other examples that you can think of that highlight the physiological effects of the body’s inability to acclimatize to extreme climates?

Into Thin Air Jon Krakauer, an experienced

climber and outdoor journalist, was sent to climb Mt. Everest in Nepal in the spring of 1996.   Late at night on the evening of May 9, 1996, after weeks of grueling climbing, acclimatization to low oxygen at high altitudes, illness, blinding snow, bitter cold, and hurricane force winds, the clients of several climbing organizations from the US, New Zealand, South Africa, and Taiwan reached an altitude of 26,000 feet before making the final ascent to the peak.

Jon Krakauer• Krakauer and his companions led by

professional climbing guides and experienced Sherpas left camp at midnight on May 10th on what developed into a perfect morning for reaching the summit. By 4:00 pm, two full hours beyond the discussed but not enforced mandatory turn around time, the weather conditions change rapidly from tranquil to blizzard in a matter of minutes. Winds are blowing with gale-force strength and as night falls the temperature with wind chill is more than 100 degrees below zero. With no shelter and a shortage of oxygen canisters, 30 individuals are exposed and freezing above 26,000 feet on the barren, icy slopes of Everest. Krakauer loses several climbing partners and climbers from other groups, and two experienced expedition-leading guides.

The Climb

Written the same day on Everest, but told from a different perspective.

Some believe That although “Into Thin Air”

was an international best-seller and Jon Krakauer is an accomplished writer and semi-professional climber, his views were distorted during the expedition and led to inaccurate accounts. Whereas Annatoli Boukreev is a more accomplished guide and his account, based on physiology alone, may be more accurate.

Who to believe?

Is it possible for some to be more physiologically disposed

to these extremes?

fin

Happy Thursday-Friday!!

• Air Mixtures• ATP• Smarter on Drugs?

Objectives

Class notes: Stayin’ Alive

The “The Death Zone”

Anatomical Terminology (Directions and Planes)

Anatomical Planes

Be able to label transverse sagittal, median, frontal coronal.

Know the difference between median and sagittal.

Happy Wednesday

1. Wrap-up of body systems

2. Survival needs3. Homeostasis and

homeostatic control mechanisms

4. Why does this guy look so confused?

Body Systems

Name of systemWhat is it made of?

(organs and Structures)

What does it do?How is it regulated?What can go wrong?How do we fix it?

Maintaining Life

• Maintaining Boundaries• Movement• Responsiveness• Digestion • Metabolism• Excretion• Reproduction• Growth

Happy Thursday!

Homeostasis and homeostatic control mechanisms

Positive and negative feedback mechanisms

Deep TroubleProject idea tighten up

What could possibly go wrong?

Human Chop Shops?

Hmmm.

Extended space travels

Stayin’ Alive

Nutrients

Oxygen

Water

Normal Body Temperature

Atmospheric Pressure

Often Imitated

It’s Friday! Already?

Do now: Define Technology

Give three more examples:

1.2.3.

It’s Monday! Already?

Do now: Define VariableA variable is

___________________What is the CSU?What is the ESU?• Technology: The

Bionic Arm• Observations• Candle Lab Again?• Format for writing

experiments

Happy Monday!!!

Lab #1 overviewCavities and liningsAnatomical

Directions and terms

Anatomical Planes

Thursday, Thursday

Do ya get it? PFM ‘s and NFM’s

Quick revisit to Positive and negative feedback mechanisms

Raising the DeadGood idea?Anatomical Planes

and Terminology

Tighten Up

• Lab #1• Cavities and linings• Anatomical Directions

and terms• Anatomical Planes

It’s Monday! Already?

1: Do now2: Observations3: Candle Lab Again?4: Format for writing

experiments

Do Now

Do now: Define VariableA variable is ___________________What is the CSU?What is the ESU?What are three ways of making

observations BEFORE you start your experiment?

A good experiment tests __ variable(s) at a time.

What could possibly go wrong?

Human Chop Shops?

It’s FRRRRRIDAYYYY, Already? Really?

• Bionic Arm?• Everest Wrap-up• Survival Needs

Review

• CSI

What could possibly go wrong?

Human Chop Shops?