Flight Physiology by Reinhart - Essay Example

Flight Physiology by Reinhart a) What is “flight physiology?” What is the difference between systemic and pulmonary circulation? Flight physiology deals with the working of the body and the mind in a flight environment. Whereas pulmonary circulation takes the oxygen depleted blood and adds more oxygen to it, systemic circulation delivers blood rich in oxygen to the parts of the body which require it. b) Why do we breathe? Breathing allows us to get rid of carbon dioxide in our body and replace it with oxygen. Oxygen is essential for converting food into energy, which the cells in our body need. c) What is the function of a baroreceptor? The primary function of baroreceptors is to detect the blood pressure in our body. Whenever there is a change in blood pressure, it sends a signal to the central nervous system. d) What is the difference between external and internal respiration? External Respiration is the process which deals with the exchange of the gases oxygen and carbon dioxide between the environment and the body. Internal respiration on the other hand is the process which involves the exchange of those two gases within individual cells in the body. e) What is the SHELL model and how does it relate to human factors and aviatin physiology? The SHELL model pertains to the relationship between the aviation environment and human factors. The SHELL components greatly assist people in avoiding accidents and a training based on SHELL components helps make best utilization of human capabilities in flight. f) Why is it important to understand the respiratory and cardiovascular systems with respect to aviation physiology? Since in aviation, cabin altitude often exceeds 34,000 feet. At this altitude, the oxygen level within the respiratory system gets dangerously low. Also, the G forces in flight affect the cardiovascular system. That’s why it’s important to understand respiratory and cardiovascular system. Bones Locate the following bones in the body: humerus, radius, ulna, femur, tibia, and fibula. Your book does not provide the location of these bones, so you will have to look elsewhere. Send a report of the general location of each of these bones.Ex. The parietal bone is located in the head, above the temporal bone. Humerus- The bone extending from the shoulder to the elbow Radius- The outer and slightly shorter of the two bones in the human forearm. Ulna- The inner and longer bone located in the forearm. Femur- The bone which extends from the pelvis to the knee. Tibia- Inner and thicker of the two bones located between the knee and ankle. Fibula- Outer and thinner of the two bones in the human leg between knee and ankle. Orientation a) What are the differences between peripheral and focal vision, and why are they important in flight safety? Whereas focal vision helps the pilot in seeing clearly in order to recognizing objects, peripheral vision helps in establishing spatial orientation. Both of them together function to gather visual information about orientation and also help in touchdowns. b) What is the physiological (or nighttime) blind spot and what can be done to compensate for it? The particular scotoma in the visual field which correlates to absence of photoreceptor cells on the optic disc is called physiological blind spot. Continuous scanning of an area with both the eyes can compensate a nighttime bloodspot. c. (Please note that the physiological blind spot is VERY different from the anatomical blind spot. Anatomical blind spot is the particular region of the retina where the blood vessels and the optic nerve connect to the back of the eye. d) What is the type of acceleration that the semicircular canals detect and the two types of acceleration the otoliths detect? Angular acceleration is detected by the semicircular canals whereas otoliths help detect linear accelerations, decelerations and gravity. e) What is your most important sense in the flight environment? Vision is the most important sense in the flight environment. f) What is the most frequently encountered vestibular illusion in flight? The most frequently encountered vestibular illusion in flight is called Leans. The pilot is often compelled to lean in the opposite direction of the turn he or she perceives. Medical Stress a) What is hypoglycemia and what are some ways to prevent it? Hypoglycemia is a stress that occurs when a person hasn’t ingested an adequate amount of nutrition. One of the best ways to prevent it is by keeping a source of packaged calories in store. Planning ahead and eating more fats and protein also helps to prevent hypoglycemia. b) What are the differences between decongestants and antihistamines? Whereas antihistamines assist in drying up secretions fro the nose and sinuses, decongestants help in reducing swelling in the nose and sinuses. c) How can a stressor such as smoking affect your night vision? Smoking releases carbon monoxide in the blood system and also prevents absorption of oxygen. The lack of adequate oxygen in blood causes hypoxia. And since hypoxia affects night vision, smoking indirectly affects your night vision. d)What is the best cure for a hangover? Although it’s said that coffee and oxygen cures a hangover, it’s not actually true. The only cure is time; about 36 hours are needed to cure a hangover. Homeostasis a. What is homeostasis? Homeostasis is the maintenance of a constant internal environment in the body in the face of the changing conditions in the external environment and also the internal environment. b) Describe the body's temperature control system. During the time when food is being broken down to be used as energy by the cells, heat is produced. Also during sleep, the organs generate heat. This heat is transferred throughout the body by blood. This temperature control system allows our body to maintain a body temperature ranging from 97 degrees and 100 degrees Fahrenheit. . Though, the average temperature of our body is 98.4 degrees Fahrenheit. c) What are the stages of sleep? There are four stages of sleep which are all categorized as NREM sleep. In the first stage, there is drowsiness. In the second stage, the body functions slow down, respiration and pulse rate slows down in the third stage while in the fourth stage, brain activity slows down. d) What are the differences between eastward and westward travel, and what direction does the body prefers? In eastward travel, the peak performance declines dramatically compared to westward travel. Additionally, in eastward travel, mean performance is more repressed than it is in westward travel. Westward travel causes the day to be lengthened artificially, which is easier for the Circadian rhythm to adapt to. That’s why westward travel is preferred by the body rather than eastward travel. e) Approximately how long should a short nap last? And do you need to nap? Naps should be timed so that it doesn’t exceed 40 minutes; otherwise, e body might get to the fourth stage of sleep. Experts believe naps are important for those people who don’t get eight hours of sleep at night. Napping also helps in boosting energy and awareness. Reflection What statements listed below are true for you? How many are true? ___ 1. I need an alarm clock in order to wake up at the appropriate time.-True ___ 2. It’s a struggle for me to get out of bed in the morning.-False ___ 3. Weekday mornings I hit the snooze button several times to get more sleep-False ___ 4. I feel tired, irritable, and stressed-out during the week.-False ___ 5. I have trouble concentrating and remembering-False ___ 6. I feel slow with critical thinking, problem solving, and being creative-False ___ 7. I often fall asleep watching TV-True ___ 8. I often fall asleep in boring meetings or lectures or in warm rooms-False ___ 9. I often fall asleep after heavy meals or after a low dose of alcohol-False ___ 10. I often fall asleep while relaxing after dinner-True ___ 11. I often fall asleep within five minutes of getting into bed-False ___ 12. I often feel drowsy while driving-False ___ 13. I often sleep extra hours on weekend mornings-True ___ 14. I often need a nap to get through the day-False ___ 15. I have dark circles around my eyes-False Acceleration a) Why are astronauts seated with their backs parallel to the ground/deck during take off? To reduce the amount of compressional forces that is exerted on the human spine. Lying in a horizontal position loads only 25 pounds of compression, which prevents spinal cord problems. b) What is greyout and what visual system is affected? Greyout causes a partial loss of consciousness, wherein the peripheral vision is affected. c) What are the human G limits for the F-18, F-16 and F-15 aircraft? F-15- 7.33g F-16- 9 g F-18- 7.5g d) Who is responsible for Crew Resource Management (CRM)? The cabin crew along with the ATC and on-ground company personnel are responsible for CRM. e) What type of hypoxia is most frequently encountered when pulling Gs? Stagnant hypoxia is most frequently encountered when pulling Gs. f) What is an anti-G strain maneuver? Anti-G strain maneuver involves two components. Firstly, the skeletal muscles need to contract as much as possible and secondly, the chest pressure is increased by expanding the lungs. AGSM helps to reduce G-stress. Atmosphere a) What are the major gases of the atmosphere? The major gases in the atmosphere are oxygen(20.95 percent), nitrogen (78.08 percent ) carbon dioxide (0.03 percent) and inert gases such as hydrogen (0.00005 percent), argon(0.93 percent), helium (0.0005 percent), krypton (0.0001 percent), neon (0.0018 percent) and methane (0.0002 percent). b) How does the temperature and pressure vary with height? Temperature falls with a rise in altitude. In the troposphere, the lapse rate is 3.56°F per 1,000 feet. The atmospheric pressure too decreases with altitude. Density of air causes more pressure at the surface of the Earth. c) What are the gas laws and why are they important to aviation psychology? The atmosphere contains a mixture of gases and there are certain laws of physics which subject these gases. These laws are called the gas laws. The human body has a number of cavities and moist air can get trapped in these cavities. The gas laws apply to those gases trapped within the body cavities. Especially in aviation physiology, the body is subjected to various forces and trapped gases in the body sometimes expand. That is why it’s important to know the gas laws. d) What is "situational awareness" (SA) and what factors can affect your SA? SA is the collective awareness of the flight crew which perceive the relationship between aircraft and the factors affecting the objective of the flight. Some factors which affect situational awareness include failure to anticipate activities the aircraft needs to execute, channelised thinking due to fatigue or hypoxia, unawareness about the performance parameters and not looking out of the windows while the plane is flying. e) What is the standard temperature lapse rate? The standard temperature lapse rate is the steady fall of temperature in the troposphere with a rise in altitude. This lapse rate is 1.98°C (3.56°F) per 305 m (1,000 feet). f) What is diffusion? When atoms or molecules of substances mix together by spreading into one another, it is called diffusion. g) What are the three physiological zones? And why is this important? The first zone is The Physiological-Efficient Zone which ranges from sea level to approximately 10,000–12,000 feet. The Physiological-Deficient Zone extending from 12,000 feet to about 50,000 feet is the second zone while the third zone is the Space-Equivalent Division, which is above 50,000 feet. Each of the three Physiological zones affects us mentally as well as physiologically, that is why they are important in aviation. Altitude a) What is hypoxia and what are the different types of hypoxia? The lack of adequate oxygen in the body’s metabolism is called hypoxia. The different types of hypoxia include Stagnant hypoxia, Hypoxic (altitude) hypoxia, Hypemic(anemic) hypoxia and Histotoxic hypoxia. b) What is the most common type of hypoxia encountered in the world of aviation? Hypoxic (altitude) hypoxia is the most common type of hypoxia encountered in the world of aviation. c) Discuss some common oxygen support systems (military or commercial) and what is cabin altitude? Some common oxygen support systems are Gaseous Aviation Oxygen which needs to be free of water, Liquid Oxygen and also Chemical Generation of oxygen, which is common in commercial aircrafts. Supplemental oxygen can be delivered either in liquid or gaseous form. A mask is required for delivering all the aforementioned oxygen support systems. Cabin altitude is also called the cockpit altitude. It’s basically the present altitude of the flight cabin. d) Where in the body can trapped gas occur? Some of the typical cavities in the body where gas can be trapped are the blocked sinuses, the gastrointestinal system and middle ears. Teeth which have cavities, abscesses, and fillings can also have trapped gases. e) What would be the treatment for an in-flight ear block on descent? On decent, some effective methods are chewing gum, moving the jaw, swallowing air and also yawning. Another technique is called the Valsalva maneuver. f) What is “oxygen paradox?" Oxygen paradox is a physiological phenomenon, occurring during re-oxygenation of a person who has suffered from severe hypoxia. Perceiving a) List and discuss the three physical properties associated with sound. Frequency is the first property of sound which basically refers to the number of oscillations per second of a sound wave. Frequency is measured in Hertz or Hz. Intensity of sound is its second property which is measured in decibels or Db. The duration of sound is the third physical property and a long duration of sound can potentially harm the ear. b) List the three regions of the ear. The ear is divided into the inner ear, middle ear and the outer ear. c) What is the anatomical blind spot? The region of the retina where the blood vessels along with the optic nerve pass through for connecting the rear part of the eye is called the anatomical blind spot. d)What are the photoreceptors (rods and cones) of the eye and how do they work? The rods and cones are the photoreceptors of the eye. Whenever light rays coming through the cornea of the eyes all into the retina, the retina uses these photosensitive rods and cones to translate light energy into electrical energy. Cones are sensitive to colors and bright light and thus aid photopic vision whereas rod cells are sensitive to low light and aids in night vision. e) In what region of the ear (outer, middle, inner) is wave energy converted to mechanical energy? Wave energy converted to mechanical energy in the outer ear. Emergencies a) What is the name of the type of loop associated with information processing? The type of lop is called a closed loop of mental processing. b) Describe our ability as humans to monitor automation. Humans by nature get distracted very easily. The human mind gets bored very quickly unless they take part in some sort of activity. The mental workload gets overloaded whenever automation is increased. Sometimes the pilot may over-rely on the automation and at other times, the pilot may get intimidated by the components involved in the automation process. In both cases, the information loops have a chance to be broken. b) During an in-flight emergency, what activity takes precedence over all others? Most important activity during in-flight emergency is flying the plane. Concentrating on flying the plane is of utmost importance, since emergencies can wait until the plane is landed on the ground. d) List two physiological sensory impairments. Deficient color vision and fatigue are physiological sensory impairments. Health a)What is the FAA medical certification process, who are the key players, and what do they do? The objective of the FAA medical certification process is to identify a pilot’s psychological, mental, medical as well as physical condition which can make the pilot unsafe for flying an aero plane. The Aviation Medical Examiners or AME’s are the key players. AME’s are medical doctors whose task is to examine the pilots. They conduct the tests, evaluate the pilots and then submit the completed file to the FAA for review. b) What is a trans fatty acid? When unsaturated vegetable fats are hydrogenated, a new type of fatty acid is formed which is called the trans fatty acid. c) What are phytochemicals or phytonutrients? Please provide an example. Phytochemicals or phytonutrients are non-nutritive plant chemicals which have inherent properties to cure or prevent diseases. Lycopene in tomatoes is an example of a phytochemical. d) Name three monounsaturated oils and state whether or not they are good for you. Monounsaturated oils help reduce the LDL, which is a lipoprotein which transports cholesterol in the blood. Three examples of monounsaturated oils are peanut oil, sesame oil and corn oil. e) What is the name of the important body "fuel" used by the brain and muscles? It is glucose. f) What does the word denial mean in the aviation world? Denial is a word which is similar to the meaning of grounded. If after evaluation, the FAA feels that a pilot cannot be given to responsibility to fly an aero plane, the word ‘Denial’ is used. However, ‘Denial’ does not necessarily mean that a pilot can never fly a plane. References Reinhart, Richard O (1992). Basic Flight Physiology. New York: McGraw Hill. Read More