Recommended
More Related Content
Similar to 01 intro & alt physics
Similar to 01 intro & alt physics (20)
Recently uploaded
Recently uploaded (20)
01 intro & alt physics
- 1. Introduction Information 1. WELCOME : Primary purpose of attendance - Flight Safety. Normal body in abnormal environment. Man – machine interface. 2. COFFEE and TEA : Crewroom. SR 2 per person / day. NO food or drink in the classroom. 3. FIRE. Evacuate via front doors or as directed by Instructor. 4. TOILETS. 5. NO SMOKING. 6. MOBILE PHONES, switched OFF 7. COURSE LEADER. 8. START TIMES and PROGRAMME. 1
- 2. Introduction Information 11. CONDITIONS : Must be present for all lectures & chamber runs. 12. PRAYER TIME ARRANGEMENTS. Location of mosque. 14. CERTIFICATES. 15. EXAMINATION: Multiple choice, 4 possible answers (only one correct). Pass mark = 60%. Failure - Re-sit different exam next day. - Recourse. ANY QUESTIONS. 2
- 3. Medical officers introduction to aviation medicine. 3
- 4. Objectives Describe the structure and layers of the atmosphere Explain the change in physical properties with ascent to altitude Define the Gas Laws applicable to the aviation environment 4
- 5. Layers of the Atmosphere EXOSPHERE IONOSPHERE STRATOSPHERE TROPOSPHERE Mt Everest 29,028 ft TROPOPAUSE 30 MILES 435 MILES 1,200 MILES 5
- 6. Functions of the Atmosphere Radiation Protection UV and sub-atomic particles Ozone Layer (~ 40K`-140K`) 3 O2 + UV <=> 2 O3 + HEAT Thermal Protection Cloud reflects IR radiation (Greenhouse) Pollutants cause excess....Global Warming Gaseous Support of Life O2 , CO2 , H2O 6
- 7. The ICAO Standard Atmosphere Where it is / at 45°N in North America. Air = dry, dust-free, stated composition Pressure (MSL) = 1013 Hpa Density (MSL) = 1.225 kg/m3 gconstant = 9.80665m/s2 Temp/alt profile +15 0C at MSL Lapse rate = 1.98 0C/1000’ to 36 089’ (= tropopause) Isothermal layer temp = -56.5 0C Rises to -46 0C at 100,000’ 7
- 8. Composition of the Atmosphere Oxygen 21% Nitrogen 78% Rare gases (eg. methane, ozone, CO2) 1% NB. Although pressure changes with altitude, this percentage relationship remains constant 8
- 9. Problems with Altitude pO2 Pressure drops pN2 Gas expands Temperature drops (Lapse rate) Sea Level 9
- 10. TEMPERATURE – DEGREES CENTIGRADE HEIGHT -6.7 15.6 feet -62.2 -51.1 -40.0 -28.9 -17.8 44 100,000 90,000 Standard 80,000 Atmosphere 70,000 TROPOPAUSE - EQUATOR 60,000 Chart 50,000 40,000 TROPOPAUSE - SA TROPOPAUSE - POLES 30,000 20,000 10,000 Sea Level -80 -60 -40 -20 0 20 40 60 TEMPERATURE – DEGREES FAHRENHEIT 10
- 11. Pressure Changes with Altitude 800 760 1013 HPa 700 600 10,000 ft – 2/3 675.3 HPa Pressure mm Hg 500 400 18,000 ft – 1/2 506.5 HPa 300 25,000 ft – 1/3 337.6 HPa 33,700 ft – 1/4 253.2 HPa 200 43,000 ft – 1/6 100 0 0 10,000 20,000 30,000 40,000 50,000 60,000 Altitude (Feet). 11
- 12. The Gas Laws Boyle : Charles : Henry : Dalton : 12
- 13. The Law of Gaseous Diffusion Henry’s Law A gas will move from an area of higher pressure to an area of lower pressure. Oxygenation within the body depends on this law. 13
- 14. Partial Pressure Dalton’s Law Air at Sea Level O2 = 21% pO2 = 160 mm Hg N2 = 78% pN2 = 593 mm Hg Other = 1% = 7 mm Hg Total = 100% = 760 mm Hg 14
- 15. Gas Expansion With Altitude. Boyle’s Law : PXV=K 800 760 Sea Level – 1/1 1013 HPa 700 600 10,000 ft – 2/3 Pressure mm Hg 675.3 HPa 500 400 18,000 ft – 1/2 506.5 HPa 300 25,000 ft – 1/3 337.6 HPa 33,700 ft – 1/4 253.2 HPa 200 43,000 ft – 1/6 100 0 0 10,000 20,000 30,000 40,000 50,000 60,000 Altitude (Feet). 15
- 16. Body Cavities Containing Gas (1) The Middle Ear Nerve to brain Eardrum Atmospheric pressure Atmospheric pressure Eustachian tube Opening to throat Atmospheric pressure 16
- 17. Climbing Pressure INCREASES Eustachian tube Atmospheric pressure DECREASES Air vents to throat 17
- 18. Descending (Normal) Pressure DECREASES Eustachian tube Atmospheric pressure INCREASES Air must enter via Eustachian tube. 18
- 19. Descending (Blocked) DECREASED Pressure PAIN ! Wall of Eustachian tube sucked in. Atmospheric pressure Eardrum sucked in. INCREASES BLOCKED. 19
- 20. Body Cavities Containing Gas (2) Middle Ear. Sinuses. 20
- 21. The Sinuses Ethmoidal sinuses Frontal sinus Maxillary sinus Sphenoidal sinus 21
- 22. Location of Sinus Cavities Frontal Ethmoid Maxillary 22
- 23. Body Cavities Containing Gas (3) Middle Ear. Sinuses. Lungs. 23
- 24. Gas Expansion in the Lungs Pneumothorax Air embolism Pneumomediastinum 24
- 25. Body Cavities Containing Gas (4) Middle Ear. Sinuses. Lungs. Gastrointestinal Tract. 25
- 26. Gas Expansion Stomach Large bowel Small bowel ? 26
- 27. Body Cavities Containing Gas (5) Middle Ear. Sinuses. Lungs. Gastrointestinal Tract. Post surgical 27
- 28. Body Cavities Containing Gas (6) Middle Ear. Sinuses. Lungs. Gastrointestinal Tract. Post surgical. Post trauma. 28
- 29. Body Cavities Containing Gas (7) Middle Ear. Sinuses. Lungs. Gastrointestinal Tract. Post surgical. Teeth. 29
- 30. Teeth Problems on Climb : Bad fillings. Abscess. Dental hygiene is important. Visit the Dentist every 6 months. 30
- 31. Prevention of Trapped Gas Problems Fly only when healthy Do not self medicate Equalise pressures frequently on descent Avoid gas producing foods, before flying. 31
- 32. Prevention of Trapped Gas Problems Never fly with a cold or sore throat. Do not self medicate. See the Flight Surgeon if you are sick. Equalise pressures frequently on descent. Valsalva or roll the jaw. Avoid gas-producing foods before flying. 32
- 33. Physical Changes in the Atmosphere pO2, Hypoxia above 10,000 ft. Total atmospheric pressure falls pN2, DCI above 18,000 ft. Gas expands. Sinuses. Ears. Stomach. Temperature falls 2°C / 1000 ft. Sea level 33
- 34. Body Cavities Containing Gas (8) Middle Ear / External Ear. Sinuses. Lungs. Pneumothorax. Gastrointestinal Tract. Hernia. Bowel. Post surgical. Teeth. 34
- 35. AEROMEDICAL CENTRE K.A.A.B. DHAHRAN 35
- 36. Remember Pain anywhere in the body DURING CLIMB = COMPLETE OBSTRUCTION. Where does this link too ??? 36
Editor's Notes
- Information 1. Action. Result. Automatic. Text wipes right by paragraph, 1 sec delay. Click Next slide. Important Points : As per slide.
- Introduction 2. Action. Result. Automatic. Text fades in by paragraph, 1 sec delay. Click ‘Any questions’ text. Click Button to Lecture 01 Physics of the Atmosphere. Click Screen to exit to Powerpoint. Important Points : As per slide.
- 22/07/12 Title Slide. Action. Result. Important Points. An understanding of our atmosphere is useful in all flying operations. It is the environment in which you will be working. To understand effects on our body caused by altitude. Information given in this lesson is essential in understanding the lessons which follow.
- 22/07/12 Objectives Slide. Action. Result. Important Points.
- Layers Slide. Action. Result. Automatic. Earth fades in. 1 sec delay, Everest zooms out. 1 sec delay, rings and titles zoom out 1 sec delay Click. Next slide. Important Points.
- 22/07/12 Functions Slide. Action. Result. Important Points. Radiation protection - prevents too much UV bombarding the Earth, also subatomic particles, known as “ionising radiation”. The heat generated in the ozone reaction explains why temperature rises in the upper stratosphere. Thermal protection - prevents heat escape and therefore us freezing (eg Mars). Solar radiation heats the ground, which warms the air above it. The ground reradiates IR radiation, which is also reflected back by CO 2 and water vapour...the “Greenhouse Effect”. Major role of heating in forming weather patterns. Gaseous support of Life - oxygen, carbon dioxide and water vapour. We have evolved to exist at the surface of the Earth where these parameters are ideal. As we ascend, these parameters change which impacts on our ability to survive and work at altitude.
- 22/07/12 ICAO Slide. Action. Result. Important Points. Physical parameters of the atmosphere are defined by the ICAO Standard Atmosphere (ICAO= International Civil Aviation Organisation). Defines an “ideal atmosphere”, which is meant to closely resemble the atmosphere at 45 deg N latitude. Describes the variation of pressure with altitude, for a given relationship between temperature and altitude. Why is this important? A standard which is internationally agreed. Used to calibrate flight instruments, especially altimeters. (Pressure/density height). Allows comparisons between performance of different aircraft types.
- 22/07/12 Composition Slide. Action. Result. Important Points. These figures are based on dry air only. Usually water vapour is also present; it’s percentage depends on humidity. This water vapour will obviously alter the relationships here by taking up this percentage - more later. For dry air, this percentage relationship holds true up to altitudes approaching 300K’.
- Problem Slide. Action. Result. Important Points.
- Standard Atmosphere Slide. Action. Result. Important Points.
- 22/07/12 Pressure Changes Slide. Action. Result. Important Points. How do we measure pressure(units)? Pressure units: 1 atm / bar = 760mm Hg = 101.3kPa = 1013mb / HPa = 14.7psi Sea-level pressures are shown on a weather map using mb. These of course vary with weather patterns. Pressure in the atmosphere is the product of 2 opposing factors: solar radiation, expands gases Earth’s gravity, contracts gases We use mmHg, which are also medical or physiological units. Most measurements of things like the oxygen pressure in your blood (which will be discussed next lecture) are in mmHg however, and therefore it is easier to use these units. Relationship between pressure and altitude is non-linear, ie. exponential Note that the greatest pressure change at lower altitudes. 18000’ is half sea level atmospheric pressure. 25000’ is one third sea level atmospheric pressure. Density follows the same pattern. Von Karman’s line at 262K’, density so low aerodynamic forces do not exist, so vehicles need jets/rockets to manoeuvre. Ask: What is the difference between Pressure and Density? Answer: PRESSURE = FORCE / UNIT AREA DENSITY = MASS / UNIT VOLUME)
- 22/07/12 Laws Slide. Action. Result. Important Points. These form the basic principles which we will use in subsequent lessons to understand the effects of altitude on the human body. We will be examining five of these Laws.
- 22/07/12 Henry’s Slide. Action. Result. Important Points. We also see this in weather systems. Winds are caused by air moving from areas of higher to lower pressure. In chemical solutions, molecules also move from areas of high concentration to low concentration. Rate of diffusion depends on: the pressure difference molecular weight, in liquid rate is proportional to the solubility of the gas Fick’s Law, in the human body, where membrane thickness and surface area for diffusion are important. Oxygen diffuses within the body and will be covered in the lesson on Respiration and Circulation
- 22/07/12 Dalton Slide. Action. Result. Important Points. Dalton’s Law states that the total pressure of a gas (in this case air at 760mmHg) is equal to the sum of the partial pressures of the constituent gases ie Total 760 = 160 + 593 + 7 (constituent gas pressures). It also states that the partial pressure of an individual gas in a mixture is equal to its relative percentage of the total pressure. ie 21% of gas particles in air are O 2, thus 21% of the total air pressure of 760mm Hg is exerted by O 2 , giving a partial pressure of O 2 of 160mm Hg, etc.
- 22/07/12 18 Boyles Slide. Action. Result. Important Points. A reminder of Boyle’s Law: At constant temperature, the volume of a gas is inversely proportional to its pressure. At 18,000’ the air pressure is half its sea level value, thus a gas will expand to twice its volume if raised to this altitude from sea level at constant temperature. At 25,000’ in the chamber, the air pressure is one third of sea level pressure. Our bodies work hard to maintain a constant core temperature. Gases trapped inside our bodies are therefore maintained at a constant temperature. Thus, gases trapped in our bodies at sea level will expand to three times their original volume as we climb to 25,000’.
- Ear (1) Slide. Action. Result. Automatic. Ear zooms in, Labels & arrows zoom in, pressure labels and arrows zoom in, 1 sec delay. Click. Next slide. Important Points.
- Climbing Slide. Action. Result. Automatic. Decrease text fades in, arrow wipes right. 1 sec delay, Increase text fades in, arrow wipes left. 1 sec delay, Quad arrow zooms in, arrows wipe down, vent text fades in. Click. Next slide. Important Points.
- Normal Descent Slide. Action. Result. Automatic. Increase text fades in, arrow wipes right. 1 sec delay, Decrease text fades in, arrow wipes left. 1 sec delay, Quad arrow zooms out, air text fades in, arrows wipe up. Click. Next slide. Important Points.
- Descent Blocked Slide. Action. Result. Automatic. Blocked text zooms out, arrow fly’s up. 1 sec delay, Increase text fades in, arrow wipes right. 1 sec delay, Decrease text fades in, arrow wipes left. 1 sec delay, Quad arrow zooms out, eardrum text fades in, arrows wipe up. Wall text fades in, arrows wipe left. Pain text flash’s 4 times. Click. Next slide. Important Points.
- 22/07/12 20 Cavities 2 Slide. Action. Result. Important Points. Gas is unlikely to be trapped in the lungs to any significant degree in any scenario in the aviation environment as the large airways conduct the expanding gas easily out of the lungs, through an open epiglottis. If, however, you were able to hold your breath during an explosive decompression this may be sufficient to cause some damage. Certainly this has been shown to occur in diving when breath is held during a rapid ascent to the surface. Damage due to rapid pressure change is known as barotrauma . The pressure differential across the lung must be 80 - 100 mmHg before tearing of the tissues will occur.
- 22/07/12 Sinuses Slide. Action. Result. Automatic. Text fades in, arrows wipe in, Ethmoid clockwise. Click. Next slide. Important Points. Sinuses are cavities in the skull.
- Sinuses (1) Slide. Action. Result. Automatic. Text & arrows zoom in, top to bottom, 1 sec delay. Click. Next slide. Important Points.
- 22/07/12 20 Cavities 2 Slide. Action. Result. Important Points. Gas is unlikely to be trapped in the lungs to any significant degree in any scenario in the aviation environment as the large airways conduct the expanding gas easily out of the lungs, through an open epiglottis. If, however, you were able to hold your breath during an explosive decompression this may be sufficient to cause some damage. Certainly this has been shown to occur in diving when breath is held during a rapid ascent to the surface. Damage due to rapid pressure change is known as barotrauma . The pressure differential across the lung must be 80 - 100 mmHg before tearing of the tissues will occur.
- 22/07/12 21 Lungs Slide. Action. Result. Important Points. Conditions which can occur due to lung barotrauma include: Pneumothorax - a tear in the lung allows air to enter the pleural cavity causing a partial collapse of the lung. This causes chest pain and shortness of breath as one is unable to take a normal breath. If the air in the chest is under increased pressure and cannot escape, it is a very serious condition called tension pneumothorax . This can be rapidly fatal if untreated. Air Embolism - a tear in the lung allows air to enter the blood vessels around the lung. Symptoms may include dizziness, shock, headache, vision loss or sudden collapse as blood flow to the brain may be interrupted. These symptoms are similar to stroke. Pneumomediastinum - a tear in the lung allows air to enter the mediastinum, the region between the lungs and around the heart. This causes pain and a shortness of breath. Subcutaneous emphysema - sometimes air may escape into other tissue planes, such as under the skin. This may cause swelling of the tissues around the neck, face and chest, giving a “Michelin Man” appearance. It feels crackly under the fingers, like cellophane paper. Treatment will require medical attention. Small amounts of air will, however, be absorbed from the pleural cavity in time. As a safety measure, and to prevent these conditions from occurring in the chamber, we ensure that we are breathing out at the commencement of any rapid decompression.
- 22/07/12 22 Cavities 3 Slide. Action. Result. Important Points. It is not uncommon to experience a little “gut” discomfort in an aircraft or in the chamber. This problem is best avoided by paying attention to your diet prior to flying. Avoid gas producing foods such as cabbage, baked beans, and fizzy drinks. On average the healthy gut may contain up to 400ml of gas. Q: At 25,000’, what is the volume of gas in the intestines? Answer: 1.2 litres!
- 22/07/12 Stomach Slide. Action. Result. Automatic. Text appears, stomach zooms in, 1 sec delay, arrow wipes up. Click. Text appears, Large Int zooms in, 1 sec delay, arrow wipes down. Click. Text appears, Small Int zooms in, 1 sec delay, ? & arrows wipe up/down. Click. Next slide. Important Points.
- 22/07/12 22 Cavities 3 Slide. Action. Result. Important Points. It is not uncommon to experience a little “gut” discomfort in an aircraft or in the chamber. This problem is best avoided by paying attention to your diet prior to flying. Avoid gas producing foods such as cabbage, baked beans, and fizzy drinks. On average the healthy gut may contain up to 400ml of gas. Q: At 25,000’, what is the volume of gas in the intestines? Answer: 1.2 litres!
- 22/07/12 22 Cavities 3 Slide. Action. Result. Important Points. It is not uncommon to experience a little “gut” discomfort in an aircraft or in the chamber. This problem is best avoided by paying attention to your diet prior to flying. Avoid gas producing foods such as cabbage, baked beans, and fizzy drinks. On average the healthy gut may contain up to 400ml of gas. Q: At 25,000’, what is the volume of gas in the intestines? Answer: 1.2 litres!
- 22/07/12 22 Cavities 3 Slide. Action. Result. Important Points. It is not uncommon to experience a little “gut” discomfort in an aircraft or in the chamber. This problem is best avoided by paying attention to your diet prior to flying. Avoid gas producing foods such as cabbage, baked beans, and fizzy drinks. On average the healthy gut may contain up to 400ml of gas. Q: At 25,000’, what is the volume of gas in the intestines? Answer: 1.2 litres!
- 22/07/12 Body (3) Slide. Action. Result. Automatic. Text wipes down, picture fades in. Click. Dental text zooms in by paragraph. Click. Next slide. Important Points.
- 22/07/12 34 Prevention Slide. Action. Result. Important Points. It cannot be overstressed to only fly when healthy, even if you only have a head cold. Self medicating may solve the problem on the ground but also may limit inflight treatment options should problems occur. Some medications may have adverse side effects such as drowsiness or decreased Hypoxia tolerance which may impact upon flying safety. See an MO on base to avoid being given incorrect advice or medications for flying. It is impossible to Valsalva too frequently on descent. However, it is important that the correct technique is used. Practice this on the ground. Gas producing foods include beans, cabbage, fizzy drinks, etc - avoid these prior to flight.
- Prevention Slide. Action. Result. Automatic. Text wipes right by line, 1 sec delay. Click. Next slide. Important Points.
- Changes Slide. Action. Result. Automatic. Pictures, text & arrows wipe in progressively clockwise starting at “sea level” Click. Next slide. Important Points.
- 22/07/12 22 Cavities 3 Slide. Action. Result. Important Points. It is not uncommon to experience a little “gut” discomfort in an aircraft or in the chamber. This problem is best avoided by paying attention to your diet prior to flying. Avoid gas producing foods such as cabbage, baked beans, and fizzy drinks. On average the healthy gut may contain up to 400ml of gas. Q: At 25,000’, what is the volume of gas in the intestines? Answer: 1.2 litres!
- End Slide. Action. Result. Nil. Click. Screen to exit to Powerpoint. Important Points.
- Prevention Slide. Action. Result. Automatic. Text wipes right by line, 1 sec delay. Click. Next slide. Important Points.