Aviation Safety 2005

1. Aviation Safety 2005 Aero Medical Briefing Larry R Boehme, MD

3. Physics of the atmosphere Respiratory physiology Trapped gas Required by FM-301aero medical training for flight personnel Altitude Physiology

4. Air

5. What is it? Where is it? How do we use it as individuals? Why is it important in aviation safety? Air

6. Physics of the atmosphere Respiratory physiology Trapped gas Altitude Physiology

7. Physics Of The Atmosphere Definition and Boundary • The atmosphere is a gaseous envelope that • covers the earth • It extends from sea level up to 1000 nautical • miles

8. Physics Of The Atmosphere Gaseous Content • Oxygen • - 20.95% • Nitrogen • - 78.08% • Trace Gases • - .97%

10. Physics Of The Atmosphere Atmospheric Pressure • The weight of all atmospheric gases creating • a measurable force at any given point on the • surface of the earth

11. Physics Of The Atmosphere Atmospheric Pressure (continued) • 14.7 psi • 760 mm of Hg • 29.92 inches of Hg

13. Physics Of The Atmosphere Benefits • Provides Protection • Supports animal and plant life

14. Physics Of The Atmosphere Divisions • Troposphere • - Sea levelto 30,000 feet at poles • - Sea level to 50,000 feet at the equator • Tropopause • - Not considered a major division

17. Physics Of The Atmosphere Divisions (continued) • Stratosphere • - Tropopause to 50 miles • Ionosphere • - 50 miles to 600 miles

18. Physics Of The Atmosphere Divisions (continued) • Exosphere • - 600 miles to 1000 miles

28. Physics Of The Atmosphere Physical Gas Laws • Boyle’s Law • - A volume of gas is inversely proportional to the pressure exerted on the • gas, with temperature remaining constant • Henry’s Law • - When the pressure over a liquid is decreased, the gas in the liquid will • also decrease

30. Physics Of The Atmosphere Physical Gas Laws (continued) • Daltons’s Law • - The total pressure of a mixture of gas is equal to the sum of the partial • pressure of each gas in the mixture • Graham’s Law • - A gas will defuse from an area of high concentration to an area of low • concentration

31. Physics Of The Atmosphere Physiological Zones • Physiological Efficient Zone • - Ranges from sea level to 10,000 feet • Physiological Deficient Zone • - Ranges from 10,000 feet to 50,000 feet

32. Physics of the atmosphere Respiratory physiology Trapped gas Altitude Physiology

33. Respiration & Circulation Definition of Respiration • Respiration is the exchange of gases between • an organism and its environment • - Supplies body cells with Oxygen • - Removes Carbon Dioxide from cells • Oxygen is used by the body for metabolism • - The burning of food material by the cells to produce energy

34. Respiration & Circulation 3 Phases of Gas Exchange • Atmosphere/Lungs • - External Respiration • Lungs/Blood • - Internal Respiration • Blood/Body Cells • - Cellular Respiration

35. Respiration & Circulation Respiratory System Components • Oral/Nasal passages • Trachea • Bronchi • Bronchial

36. Respiration & Circulation Respiratory System Components (continued) • Alveolar Ducts • Alveoli • - Air Sacs • - 300 million • - Surrounded by capillaries • - 1 cell thick

38. Respiration & Circulation Internal Respiration • An exchange of gases between the lungs and • blood • All gas movement is dependent on the • difference in the partial pressure of that • particular gas • - Dalton’s Law

39. Daltons’s LawThe Total Pressure of a Mixture of Gas Is Equal to the Sum of the Partial Pressure of Each Gas in the Mixture.

40. Dalton’s LawPtotal = P1 + P2 + P3 ---

41. Respiration & Circulation Internal Respiration (continued) • There are 4 major gases always present • in the lungs • - Nitrogen @ 573 mm of Hg • - Water Vapor @ 47 mm of Hg • - Carbon Dioxide @ 40 mm of Hg • - Oxygen @ 100 mm of Hg

42. Respiration & Circulation Internal Respiration (continued) • Partial pressure of oxygen at sea level • maintains an arterial oxygen saturation • of 96% - 98%

43. Respiration & Circulation Internal Respiration (continued) • High partial pressure of oxygen (100 mm) • diffuses through the air sac wall into the • blood • High partial pressure of carbon dioxide • diffuses from the blood to the alveoli

44. Respiration & Circulation Circulatory System • The circulatory system is responsible for • transportation of blood through out the • body

45. Respiration & Circulation Bloods Components • Plasma • - 90% water • Solids • - Primarily Red Blood Cells

46. Respiration & Circulation The Red Blood Cell (continued) • The ability of the hemoglobin to become • oxygen saturated is dependent on alveolar • oxygen partial pressure • - Which is dependent on the ambient barometric pressure • Normal oxygen saturation goes down as a • result of decreasing atmospheric pressure

47. Respiration & Circulation Cellular Respiration • The exchange of gases between the blood • body cells • Partial pressure of oxygen in the cells is • lower than the partial pressure of oxygen • in the blood • - Oxygen is off- loaded to the cells (Graham’s Law)

48. Respiration & Circulation Cellular Respiration (continued) • Partial pressure of carbon dioxide in the cells • is higher than the partial pressure of carbon • dioxide in the blood • - Carbon Dioxide is off- loaded to the blood (Graham’s Law)

49. Graham’s Law A Gas Will Diffuse From an Area of High Concentration to an Area of Low Concentration.

50. Respiration & Circulation Bloods Function • Blood supplies each cell with • - Food • - Water • - Oxygen • Blood transports waste material from cells