[ ] February 17-18, 20-21, 2014

AVIATION, HIGH ALTITUDE, AND SPACE PHYSIOLOGYDALTON’s LAW

In a gas mixture, the pressure exerted by each individual gas in a space is independent of the pressures of other gases in the mixture.

The partial pressure of a particular gas is equal to its fractional concentration times the total pressure of all the gases in the mixture.

Standard Barometric Pressure (Dry Gas) = 760mmHg (sea level atmospheric pressure)

N2 = 79% pO2 = 20.93% pCO2 = 0.04%

BREATHING AIR

As altitude increases, the barometric pressure decreases but fraction for each gases remains the same

Athletes’ training to increase oxygen tension and endurance Acclimatization: Patient hyperventilates = decreases pCO2 in

air (from 35-45 mmHg to as low as 10 mmHg) at 10,000 ft. Critical oxygen level: 90% At more than 10,000 ft above sea level: Hypoxemia

Factors that decrease the pressure of the gases in the atmosphere: Vapor pressure

o When we inhale, the air is humidified by the water present in the airway (nose, trachea)

o 47 mmHg (760 mmHg - 47 mmHg = 713 mmHg)o pO2 in trachea = 149 mmHg

Carbon dioxide (and other gases)o Produced in the tissue after oxygen is metabolizedo Excreted CO2 dilutes further the partial pressure of

gases inhaledo Fraction of CO2 increases and decreases fraction of

O2 (imagine mo si CO2, O2, at Other gases sa isang alveoli tapos dahil may kusang nabubuong CO2 sa loob, tinutulak nila si O2 at Other gases palabas kasi wala nang space)

o pO2 in alveoli = 104 mmHg

BREATHING PURE OXYGEN

EFFECT OF HIGH ALTITUDE ON ARTERIAL OXYGEN SATURATION

Blue line - Breathing room air Red line - Breathing pure oxygen When breathing pure oxygen, the decline of arterial Oxygen

saturation starts at above 30,000 ft instead of above 10,000 ft

ACUTE EFFECTS OF HYPOXIA: 12,000 ft: drowsiness, lassitude, mental and muscle fatigue

headache, nausea and sometimes euphoria 18,000 ft: twitching and seizures 23,000 ft: coma à death Other important effects:

o Decreased mental proficiencyo Decreased judgemento Decreased memoryo Decreased performance of discrete motor

movements

ACCLIMATIZATION TO LOW pO2:***The body tries to improve all the body processes to compensate for low pO2

1. Great increase in Pulmonary Ventilationo Hyperventilation (deep and fast) - the tension

increases by 1.65x normal during the first few hourso Decreases CO2 à Respiratory Alkalosis à Metabolic

Acidosis as compensatory mechanism à More hyperventilation

2. Increased number of Red Blood Cellso Increases O2 carrying capacity

3. Increased diffusing capacity of the Lungso Increases surface area

4. Increased vascularity of the peripheral tissueso Angiogenesis

5. Increased ability of the tissue cells to use oxygen despite low pO2

***People in high altitude area have small body mass, or are barrel-chested

EFFECT OF SUDDEN ASCENT TO HIGH ALTITUDE:1. Acute Cerebral Edema

a. Local cerebral vasodilatation à increases the hydrostatic pressure in the cerebral vascular bed à causes transudation of fluid into interstitial space

2. Acute Pulmonary Edema a. Hypoxic pulmonary vasoconstriction (portion of

lungs not ventilated)

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[ ] February 17-18, 20-21, 2014

b. Breathing oxygen usually reverses the process CHRONIC MOUNTAIN SICKNESS:

***Polycythemia - increased RBCs

EFFECTS OF ACCELERATORY FORCES ON THE BODY: Centrifugal Acceleratory Forces

o f = mv2/ro The “G” forceo 1G = if equivalent to your own weighto Force is 5x your weight = 5Go Force is on your head = Negative G

Effects on the Circulatory Systemo The most important effect is on the Circulatory

system o Blood accumulates at the lowest part of the body à

Bipedal edemao When blood stagnates at the lowermost part à

Dizziness, Lassitude, Drowsinesso Acceleration greater than 4-6 G causes “blackout” of

vision within few seconds à unconsciousness Effects on the Vertebrae

o Fracture occurs at 20 G Negative G

o Rupture of vessels in the eyes

PROTECTION OF THE BODY AGAINST CENTRIFUGAL ACCELERATORY FORCES:

Leaning forward to compress the abdomen Special anti – “G” suits

o Inflating compression bags applies positive pressure to the legs and abdomen as the “G” increases.

The limit of safety should still be less than 10G

EFFECTS OF LINEAR ACCELERATORY FORCES ON THE BODY: Acceleratory Forces in Space Travel

o Astronauts in semi-reclining position à decreases the “G” effect since they are in the transverse axis of the acceleratory force

Deceleratory Forces Associated with Parachute Jumpso Initial jump = 0o Speed becomes fastero Release of chute à traction à counter force to “G”

o Parachute jumpers bend their knees when they land on their feet à distributes force of impact to different parts of the body

Weightlessness in Spaceo State of near zero G : microgravityo Physiologic problems of weightlessness

Motion sickness during the first few days of travel

Translocation of fluids within the body Diminished physical activity

o Effects of prolonged stay in space Decrease in blood volume Decrease RBC mass Decrease muscle strength and capacity Decrease maximum cardiac output Loss of calcium and phosphate from the

bones

Note-taker: Roy Ang, Tristan John Guston

“It takes time to hoard courage. Courage to overcome the fear of overwhelming risks and consequences for every decision we have to make. You cannot force it to

appear but you can wait until you are certain that you have the right equipment and gears for the upcoming battle you’ll have ti face, the battle of resolve to

accept whatever results your actions will yield today, tomorrow, and for the rest of your life.”

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The red cell mass and hematocrit become exceptionally high

The pulmonary pressure becomes greatly elevated

The right side of the heart enlarges and fails

The peripheral arterial pressure begins to fall

CHF ensues DEATH

[ ] February 17-18, 20-21, 2014

DEEP SEA DIVING AND HYPERBARIC CONDITIONSREVIEW:***Important Physical Principles (DEEP SEA DIVING)

- Boyle’s Law - Volume : Pressure (inversely proportional) In the process of ventilation: decreased pressure in

lungs allows ventilation to happen. In the process of expiration: The negative pressure

allows for the ingress of air in the atmosphere to the lungs.

- Dalton’s Law - fraction of partial pressure of gas is always constant and equal to 100%

In the atm pressure, 78% (4/5) for nitrogen, 1/5 for O2, <1% for CO2 and inert gases = 100%

Therefore, atm pressure may decrease but fraction remains the SAME.

- Henry’s Law - when there is increase in partial pressure, amount of gas dissolved in tissues also increases

All dissolved BUT not necessarily metabolize.

*** Relationship of Pressure and Volume to Sea Depth- The pressure at the bottom of a column of liquid is

proportional to the height of column, the density of liquid and acceleration of gravity

- For each 33 ft. of seawater, ambient pressure increase by 1 atmosphere

In Space physiology, 1atm pressure (760mmHg) at sea level and as you go high and increase the altitude, the atm DECREASES, opposite to deep sea diving in which as you go down or below sea level, the atm INCREASES.

Therefore, as you go deep, the pressure in the lungs INCREASES to compensate for the increasing pressure outside the lungs.

- In a breath-hold dive, the volume of gas in lungs is inversely proportional to depth attained

- At 33 ft (2atm), the lung volume is cut in half By BOYLE’s LAW (volume/pressure)

pressure volume

- The deeper it gets → higher atmospheric pressure → lower

volume of lungs (Boyle’s law) Using compressed air to counteract the

pressure outside the lungs

***Effect of High Partial Pressure of Individual Gases on the Body (N, O2, CO2)

1. Nitrogen Narcosis (on compressed air) 120 feet: diver exhibit joviality and lose many of her

cares. 150-200ft: diver becomes drowsy 200-250ft: diver becomes too clumsy to perform the

work required Beyond 250ft: the diver becomes almost useless “raptures of the depths” (nitrogen narcosis is the

same as alcoholic intoxication and anesthetics) At sea level, which is equivalent to 1atm

(760mmHg), we accumulate 4/5 of nitrogen. In nitrogen narcosis, for example, at 133ft which is 5atm (5 x 760=3800mmHg), 4/5 of 3800 is the nitrogen accumulation which is toxic.

Also similar to gas anesthetics, since it dissolves in fatty substance in neuronal membrane. Nitrogen and other gasses prefer areas with high lipid content.

2. Oxygen Poisoningo When the pO2 in blood rises above 100 mmHg, the

amount of O2 dissolved in blood increase markedly (HENRY’S LAW)

In the oxyhemoglobin dissociation curve, when the O2 is very high, normally it only receives a certain amount BUT when O2 is delivered continuously, the O2 buffer system fails, therefore all O2 will be reabsorb by the tissues (no regulation). PROBLEM: presence of MOLECULAR O2 (should be converted to an active form first before it can be metabolize)

Some Molecular O2àconverted to O2 FREE RADICALS (like peroxide,superoxide)àionizing effect (bad)àdestroy tissues (majority: lipid rich tissues like neuronal membrane-brain)

Our body have FREE RADICAL SCAVENGERS (catalases, peroxidases, superozide desmutases)àdestroy extramolecular O2. BUT in case of compressed air at 4atm, too much O2 and not enough scavengers to counteract the high O2 free radicals.

a) Acute O2 Poisoning (manifestations related to BRAIN)

- Nausea, dizziness, muscle twitching, disturbance of vision, irritability and disorientation- Seizure and comma may occur in 30-60 min.- occurs when exposed to a barometric pressure of greater than 2atm- Effects increases as the subject increases effort because the muscles will require more oxygen (eg, people drown faster when they are in a panic)- “oxidizing free radicals”:

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[ ] February 17-18, 20-21, 2014

a. H2O2

b. Superoxide - occuring in patients in less than 2atm,

b) Chronic O2 Poisoning (manifestations related to PULMONARY CIRCULATION) Giving too much compressed air (1-2 atm)

for a longer time. This occurs longer time and LOWER O2

tension.

3. CO2 Toxicityo Occurs in diving helmet (rebreathing exhaled CO2)o Divers can tolerate as much as pCO2 of 80 mmHg by

virtue of compensatory hyperventilation At 80mmHg,it send signals to brain

(stimulatory) that there’s increased CO2àhyperventilation (more than 80mmHg, effect on brain is oppositeàdepressing effectàstop breathingàCO2 accumulationàseizure,twitching,death.

Decompression Sickness- Significant quantities of nitrogen bubbles that develop in the

body fluids either intra- or extracellular during ascend - “bends”, “chokes”, Caisson disease, Diver’s Paralysis,

Dysbarism*** Basic Principles

1. N is not metabolized by the body- stays in tissue (O2 is metabolized)

2. N is 5 times as soluble in fat as water - majority is dissolved in fat3. At sea level, almost exactly 1L of N is dissolved in

the entire body

Gaseous pressures both inside and outside the body, showing (A) saturation of the body to high gas pressure when breathing air at a total pressure of 5000mmHg, and (B) the great excesses of the body pressures that are responsible for bubble formation in the tissues when the lung intra-alveolar

pressure body is suddenly returned from 5000 mmHg to normal pressure of 760 mmHg

- In Deep sea diving (pressure is about 5000mmHg or 6atm) → diver inhales from a decompression tank so that pressure in lungs can approximate with that of the atmosphere so that the lungs will not collapse

- if diver does not use tank, because of the increased pressure, it compresses the lungs causing atelectasis→ Majority of compressed air is Nitrogen (4L)→ Nitrogen will be dissolved in fat tissues and will stay there (patient does not feel effect yet → upon ascending to sea level, there is a discrepancy in the pressure of gas in the lungs and in the atmosphere → by virtue of diffusion, the pressure has to be balanced → Nitrogen from the tissues will be released in the body and in the circulation as bubbles (principle #1:N is not metabolized so it’s the first one to go out) → plug the blood vessels(emboli)

- The principles underlying the formation of bubble: In the figure A, the diver’s tissues have become equilibrated to a high dissolved nitrogen pressure (3918 mmHg), as long as the diver remains deep beneath the sea, the pressure against the outside his or her body compresses all the body tissues sufficiently to keep the excess nitrogen gas dissolved.

- But when the diver suddenly rises to sea level (figure B), the pressure on the outside of the body becomes only 1 atm (760 mmHg), while the pressure inside the body fluid are the summed pressure of the gases which is 4065 mmHg. Therefore, due to this discrepancy, gases can escape from the dissolved state and form actual bubbles, both in the tissues and in the blood where they plug many small blood vessels.

*** Symptoms of Decompression Sickness1.Majority present with pain in joints and muscle of legs and arms

- 85-90%- Bubbles plug the blood vessels in the joints → presenting as pain in joints and muscles of legs and arms → Cramps→ “BENDS”(unable to bend knees)

2. Dizziness, paralysis and syncope- 5-10%- Plug blood vessels in the brain → dizziness, paralysis, syncope → “DIVER’S PARALYSIS”

3.Serious shortness of breath and severe pulmonary edema (air embolism)

- 1-2%- Plugs blood vessels in the lungs → pulmaonary/air embolism → shortness of breath and pulmonary edema → “CHOKES”

***How to prevent or treat Decompression Sickness1.Very slow ascent

- If 1 hr in 100 ft.= 3 hrs to ascend (so that pressure in the lungs adjust to pressure in atmosphere)

2.Tank decompression

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[ ] February 17-18, 20-21, 2014

- fast ascent (no chance of slow ascent)- Put the diver into a pressurized tank and then to lower the pressure gradually back to normal atmospheric pressures (simuation of variable pressures seen in “very slow ascent”)- Treating divers whom symptoms of decompression sickness develop minutes or even hours after they have returned to the surface

3.Hyperbaric O2 Therapy - Drive N out and let the O2 occupy the space - Applicable for patients with gas gangrene (eg. Caused by C. perfringens) and with embolism but not much employed in decompression sickness

***SCUBA- Developed by Jacques Cousteau- S elf- C ontained U nderwater B reathing A pparatus - The gas tube is closed and only opens when the diver inhales- Principle- 2 tanks trying to mix O2 and N ,sometimes helium to prevent

toxicity of N and O2. 1st inhalation is creating a mixture, 2nd is that it limits the pressure (lungs have lower

atm pressure compared outside pressure) Gauge: Pressure in tank is greater than the lungs

(Breath actuation-the tank delivers O2 then stop/not continuous).

Note takers:EmKDEGG P

“If you try to look too far away, you won’t be able to see where you’re walking.”~Scarlet Fragment

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[ ] February 17-18, 20-21, 2014

SPORTS PHYSIOLOGY

Gender and Exercise Muscle strength, pulmonary ventilation and cardiac output

vary between 2/3 – 3/4 of the values recorded in men. When measured in terms of strength per cm2 of cross-

sectional area, the female muscle can achieve almost exactly the same maximal force of contraction as that of male.

Men are stronger because of muscle mass. Men and women have the same strength but because of the bulk

of the muscles present in men which is about 40% greater compared to women then men have stronger muscle strength, stronger pulmonary ventilation and higher cardiac output.

1. Testosterone Powerful anabolic effect Increases deposition of proteins in the different

areas increasing bulk of muscles Power surges for men will be far more superior compared to

women because they have more protein content in the body. The more deposition of protein allows the glycogen to deposit in the muscles which are now used for energy source in power surges.

2. Estrogen Increases deposition of fat

Fat helps the females to become more buoyant during swimming Fat allows female to have greater endurance during long activity

Muscle in ExerciseStrength

Contractile strength Holding strength – applying stimulus over a

contracted muscle Maximum contraction a muscle can have is 3-4 kg/cm2 of

muscle Athletes have cramps due to repeated stimulation during

maximal contraction

Power Determined by muscle strength, distance of

contraction and number of contractions/min Strength exerted over time

Power usually diminishes in time.

Endurance Length of time you can perform an activity up to

time of exhaustion Depends on nutritive support Eg. Marathon – take a good amount of

carbohydrates then followed by protein and lastly fat

Muscle Metabolic Systems in ExerciseATP: source of energy 3 phospate bonds Energy comes from the phosphate bond and not from the

phosphate

Phosphate bond liberates about 7,300 of energy source

1. Phosphocreatine – Creatine System Phosphogen energy system: in effect during the

first 8-10 sec Generate 4 moles of ATP/min

Majority of the ATP usually comes from Phosphocreatine – Creatine System

2. Glycogen Lactic Acid System: in effect during the first 1.3 – 1.6 min

Glycolysis à (2) pyruvic acid à Lactic acid 2.5 moles of ATP/min Use to replenish depleted energy during power

surges

3. Aerobic System Oxidation of foodstuffs in the mitochondria 1 mole of ATP/min Used for long events (marathon)

Recovery of the Aerobic System After Exercise In just 4 minutes you can already consume all the energy

source (glycogen source) that is stored in your body. First minute: 2 litres of oxygen

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[ ] February 17-18, 20-21, 2014

Succeeding minutes: 9 litres or more

Oxygen Debit

Compensation of the body is usually pulmonary ventilation to increase the oxygen reuptake

Overdoing of pulmonary hyperventilation à blowing off of CO2 à Severe Respiratory Alkalosis à dizziness à collapse

Recovery of Muscle Glycogen

During 2 hours of exercise carbohydrate would be the riches source of glycogen to recover the ATP that has been depleted.

Study shows that those who have finished 2 hours of exercise given high carbohydrate diet compared to fat and protein and those of with no food, the fat and protein diet is almost similar to that given no food after recovery.

The best way is to give high carbohydrate diet before or after exercise to recover the amount of glycogen that has been depleted during exercise.

Nutrients Used During Muscle Activity

Note Takers:ANG, A.DAGDAGEN, R.

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Things that shouldn’t be broken:1. HEARTS2. PROMISES3. Condoms

[ ] February 17-18, 20-21, 2014

MUSCLE METABOLIC SYSTEMS IN EXERCISE

Recovery of the aerobic system after exerciseOxygen debt - an increased demand for pulmonary ventilation should be replaced by hyperventilation***During the first 2 hours of exercise we consume glycogen stores and then the next source will be the carbohydrates, the protein and fat will be replaced after 5 days

Carbohydrate is used during the first few seconds Fat is used during the next few hours of exercise Protein is the last energy source used.

Muscle Development in Exercise Exercise has no effect on the muscle unless you carry a weight Restrictive training- a form of muscle conditioning where it

increases muscle mass With weights included = there is an increase muscle mass =

there is a corresponding increase in strength

Importance of Maximal Resistance Training Muscle mass increase in 30 percent during first 6-8 weeks and

also equivalent to increase in muscle strength It increases the size rather than the number of the myocytes The muscle itself does not increase, the myofibrils will

increase then the muscle will undergo hypertrophy and thus there will be an increase in size

The mitochondrial enzyme increases by 120 percent, the increase in the number of the mitochondria will compensate for the hypoxia of the muscle. It follows that the increase in muscle size will increase O2 demands and that mitochondrial enzyme is a must

Increase in phosphogen metabolic system It is the one in use in power surges To be able to supply the power needed, muscles have an

increase in stored triglyceride and glycogen For longer endurance training

Fast twitch and slow twitch fibers Noted that we cannot increase these 2 by training The genes will dictate the presence of the amounts of the

muscle fibers fast and slow Different athletes have different numbers of fast twitch and

slow twitch fibers

Fast twitch We use this in sprints Fast twitch fibers are 2x larger The phosphagen and glycogen-lactic acid system are 2-3x

more active in fast twitch fibers

Slow twitch Aerobic system is being used, mainly for endurance Muscles that are used during marathons There is greater number of capillaries in the vicinity of slow

twitch fibers For endurance training

Average male - has higher fast twitch fibers than females

Respiration and exercise Increase in oxygen consumption and pulmonary ventilation Respiration increases as much as 40 to 50 percent in exercise

The effects of exercise to pulmonary capillaries At rest some capillary remains closed During exercise, the unperfused capillaries opens up to receive

increase of blood a process called- recruitment - followed by a process called distention

Blood Gases in ExerciseIn well trained athletes, the blood gases during exercise are normal compared to an average person

Effect of smoking before exercise causes 1. Constriction of terminal bronchioles2. Increase fluid secretion in the bronchial tree3. Paralysis of the cilia

Cardiovascular system in exercise Refers to the muscle blood flow There is a decrease blood flow in tonic contraction due to the

constriction of the arteries In cases of sustained contraction it will result to cramps since

the blood cannot be delivered due to the impediment of the muscle to the arteries

A good example would be the process of jumping whereby in flight, the leg muscles are contracted which constricts the arteries and the flow of blood towards the muscles and during the process of landing an additional force of contraction exerted by the muscles which will further impede the blood flow to the muscles. Repeated actions of jumping will then result to cramps.

Work output and O2 consumption 1. There is an increase in the chamber of the heart by 40 percent2. Increases the muscle mass which is caused by muscle

hypertrophy3. Stroke volume, CO

a. Stroke volume - results from larger muscle massb. CO is increased during exercisec. In resting stage - the muscle mass won’t go back to

normal, the SV is elevated, cardiac output and BP is increased and normally the patient is hypertensive but is then normalized through compensatory mechanism by lowering the heart rate. It is the reason why marathoners have lower heart rate due to the compensation for the SV increase, it tries do decrease the heart rate thus cardiac output remains the same

d. During exercise - the heart rate will increase as a compensation which in turn will increase the CO

Heart disease and old age on athletic performanceCHF, HPN can have an effect on the athletic performance of people with advanced ages

Body heat and exercise

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[ ] February 17-18, 20-21, 2014

Heat stroke Due to increased body temperature due to physical activity

plus hot weather results to overheating of the body. There is an increase in temperature The oxygen demand increases and the increase in metabolism

is converted into heat In hot conditions- there is a double effect, the tissues in the

nerve is overheated

Body fluids and salt and exercise Loss of:

3 percent of body weight can diminish performance 5 to 10 percent- rapid decrease in weight can be serious

Remedy: Aggressive replacement of Na and K vs. Sweat gland acclimatization

Drugs and athletes Caffeine

A stimulant Rumors say that it can improve performance

Androgen Banned Increases the performance Stimulant

Amphetamines Stimulants Overuse with cocaine can decrease the performance Small amounts can stimulate and improve performance

“Kung binasted ka dati ng nililigawan mo at kinamusta niya ang lovelife mo ngayon, eto ang ibanat mo sa kanya-Eto hindi maganda, parang IKAW”

“Kapag sinabing FYI - For Your Information agad?Di ba pwedeng Forever YOU and I muna?”

Last na. . . . .

Bf and Gf talking:Gf: if bibigyan kita ng chance na halikan ako, saan mo ako hahalikan?Bf: (smiles) sa simbahan

Note takers:Mikoy DulayMarc Keane Gaces

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