This research paper has done an in-depth analysis of the physiological effects upon the respiratory system as well as the gastrointestinal tract. The examination has also been carried out on the different diseases or conditions associated with altitude differences as well as flight. Oxygen consumption, equipment used and planning have been considered. An analysis has been done on the crew resources duties, the long-term and shorter altitude effects on the teams as well as the patients. Broadly, this paper gives insight on the health issues that aviation personnel should consider when evaluating the fitness of their passengers. To give a clear view of this issues, the paper gives an elaborate and clear review of these issues.
Keywords: health, aviation, physiological, circulation
Introduction to Aviation Physiology
In adapting to its environment, the human body has very incredible abilities. For changes in the barometric pressure variations in different habitats, visible temperatures changes, external pressure changes, space motions as well as shifts in the posture about gravity, and other external and internal changes, the human body acclimates to make all these adjustments work in its favor. The body while meeting the changing requirements of energy for the various mental and physical activities performs all of these adjustments. For chronic and acute oxygen reductions, the human body makes adjustments by enhancing the red blood cells production, improving the rate of respiratory as well as increasing the chances of the chemicals in the blood. Even with all these measures and adjustments, lack of sufficient oxygen supply would lead to death in about 5 to 8 minutes. The body compensatory mechanism demands are many and of great enormity in aviation.
Barometric pressure changes, temperatures changes, higher speed movements and in three dimensions are among the environmental changes that bring about physiological changes of significant magnitude. Over the years, versatile aircraft have been made because of the advances in aviation technology and engineering. Because human beings are meant to terrestrial life, they must create a way to survive the physiological and environmental changes. Cabins of higher pressures as well as supplemented supply of oxygen are among the physical aids that have been introduced within an aircraft to reduce mental and physical stress (Brown, 2015). The paper concludes that it is genuinely important that we understand the human behavior while in flight so as to contribute to efficient flights and safety of the passengers and the crew.
Respiration and Circulation
All the human body functions are affected whenever a person is exposed to the various aerial stresses like the physiological and physical changes. The respiratory and the circulatory system are the most affected. With that, it is significant that everyone is aware of the functioning of these systems and get familiar with its affectations.
The concept of respiration
Respiration is hypothetically defined as the exchange of pure air and carbon IV oxide that occurs between the living organism and the environment it live, and it relates with the circulation system of the living organism. Carbon dioxide elimination from the body and absorption of oxygen from the atmosphere are the more prominent respiration features. The respiratory systems are made up of the trachea, lungs, a series of conducting pipes known as bronchi and their small tributaries, windpipe, mouth, and the nose. Air gests through the nose, a place where it will be warmed, moistened and cleaned so that the foreign particles are eliminated.
The air is then passed down the throat to the trachea into the bronchial tubes as well as the lung. The lungs have about sixteen bronchial tubes that get smaller as they progress. The air sacs about 300000 that are small but very numerous in quantities are located at the end of each bronchioles tube. Even though they look smaller within the lungs when removed one small air sac could cover a tennis court when put in a rectangular position. The air sacs that are constructed of a fragile membrane that is 1/50000th of an inch thick have a densely populated network of capillaries that are very tiny. Around an air sac, these small capillaries look like blood. Because of the thin membrane, oxygen and other gasses can easily penetrate the membrane into and out the capillary and the blood (Jelsma, 2015). It is where diffusion takes place. To produce energy by burning food material, the cells within the human body require sufficient oxygen. The conversation of oxygen and blood sugar into water and carbon dioxide is known as metabolism.
The carbon dioxide produced from such reactions should be removed from the body. Oxygen from the atmosphere or the environment is received by the lungs and diffused into the body. On the other hand, the blood has the function of releasing the carbon dioxide into the lungs so that it can exhale into the atmosphere. All blood cells that are low in oxygen receive the oxygen that is inhaled as it is transported. The introduction of the oxygen into these blood cells ensures that metabolism takes place and hence carbon dioxide is released and carried to the lung and exhaled into the atmosphere.
Movement of Gases in the Respiratory System
The exchange of gasses between the atmosphere and the lungs is known as external respiration. A healthy human body would inhale about thirteen trillion molecules of oxygen. The enormous number makes the molecules that are transported into the lungs quite unimaginable. The partial pressure principle is used to explain this, and partial pressure is only to some molecules that are available to be exchanged. The gaseous physiology pressures rely on the concentration of the molecule in the atmosphere as well as in the lungs. Oxygen partial pressure forces the oxygen to diffuse from through the air sac into the blood cells. 20% of the total atmospheric pressure is the partial oxygen pressure; approximately 152mm at sea level (Reinhart, 2007). The human lung has other gasses that are responsible for exerting pressure when a breath is drawn into the lungs hence the oxygen pressure will not remain the same.
Some of the gasses are the carbon dioxide as well as water vapor at 40mm and 47mm respectively. As it reaches the lungs, these gasses displace the oxygen thus the air sac level pressure of oxygen is reduced to 102mm. Grahams law indicated that an area recording very high pressure will introduce a force towards an area with limited gaseous pressure. Keeping that in mind, the gasses will be obliged to move back and forth across the air sacs. The oxygen’s higher partial pressure will now be able to diffuse through the air sacs walls and into the blood cells, and it will further raise the oxygen partial pressure in the blood that has left the cells and is low in oxygen. The pressure will be increased from 40mm to 102mm. When this is taking place, the carbon dioxide higher pressure of about 47mm within the blood will force some of the carbon dioxides to move into the air sacs where the carbon dioxide pressure is at a stable 40mm.
The same principle would apply to the exchange of gasses from the blood to cells; that is internal respiration. The oxygen high arterial blood pressure forces it to diffuse from the blood into the cells (Reinhart, 2007). The carbon dioxide high partial pressure within the cell diffuses into the blood for transport into the lungs because of metabolism.
Although simple, the respiratory system of the human body works efficiently. It assists the body to function and adjusts accordingly to the different changes in environments. However, the body cannot adjust as quickly to these physiological changes, therefore must be allowed adequate time or else would lead to affectations. In order to compensate for these constitutional limitations, it is significant that we master appropriate measures to be taken at each stage.
Gastrointestinal Intestine Tract
The gastrointestinal tract is the path that is followed by food from the mouth, through the gut, to the stomach, the small intestines, and the large intestines where nutrients are absorbed from the ingested food into the body. After which, the left over is passed through the rectum where excretion takes place. The gut is the first pathway’s first section. Food passes it from the mouth to the stomach for storing. The esophagus is a conduit and acts as guidance to the chewed and swallowed food. At the stomach, the food is stored for a while as it awaits digestion. The stomach contains the gastric juice that is used in digestion. Keep in mind that the stomach does not absorb any food. Through peristalsis, the stomach pushes the food into the small intestine. The duodenum, jejunum, and ileum are the parts of the small intestine. Within these, nutrients are absorbed into the body after being mixed with secretions.
The food received from the stomach is treated by enzymes and pancreatic juice by the duodenum. From its wall, the duodenum also mixes duodenal fluid into the food. These are then further passed into the jejunum. The second part of the small intestine is the jejunum, and it’s about 10 feet in length. It assists in breaking down the food into smaller elements so as to continue the process of digestion. The significant chunk of foods and liquids are absorbed in the last part of the small intestine. It is about 10 feet long, and it’s the third portion of the small intestine. The colon receives the remaining part of the food through the terminal ileum. Near the appendix is the start of the colon. The large intestine through peristalsis moves the waste products into the rectum for evacuation (Williams, Kuipers, Mukai and Thirsk, 2009). The primary function of the large intestine is to store the waste products as well as absorption of water and electrolytes.
An overview of the autonomic nervous system, as well as the GI tract changes and effects that happen periodically in times of motion sickness, has been provided in this paper. Motion sickness is a condition that is quite varying among different people and even within them. Different individuals experience different stimuli. Among the standard resolution disease, syndrome symptoms are vomiting. When one is vomiting, he should be secluded and put at a comfortable position. With that, the physiological changes response among people also varies. During motion sickness the gastrointestinal changes and the nervous system experience varying symptoms. Arguably the motion sickness physiological expression is mediated by the autonomic nervous system. The stomach shuts down in response by reducing the normal gastric mayo-electrical activities as well as delaying the emptying of the gastric when nausea is the predominant symptom of motion sickness.
When on a flight, most people are frightened and get stressed a lot. Stress causes guts to go into spasms. Stress can also cause increased acidity in one’s stomach which may cause indigestion The mill in one’s stomach can cause him or her stomach to shut down thereby making them nauseous. When this happens, one will have constipation and diarrhea.
Impacts of Reduced Pressure at Altitude
Whenever the body moves to a high altitude environment, some adjustment must occur so as to limit the atmospheric pressure and maintain the consistency in the body tissues (Socha et al., 2015). When the pressure around the body is subsequently limited without proper protection of the body, the valuable adjustments will not apply.
It is a disease of air found in the body cells or tissue. Without supplemental oxygen, anyone flying 12000 feet above sea level in an unpressurized aircraft is at risk of acquiring hypoxia. It is caused by insufficient or reduced pressure on the body that is not well protected. It is commonly caused by an inadequate oxygen in the inhaled air in flight (Kerkut, 2013). When a pilot gets engrossed to other duties and does not indulge in realizing the symptoms, he or she would be profoundly affected. In several occasions, the results of the reduced pressure of the unprotected body in flight are caused a limited amount of oxygen inhaled in the air. There is usually a great danger whenever the pilot fails to observe the initial symptoms in such people since it can lead death in some cases.
Hypothetically, a victim of hypoxia will always seem to increase the rate of breathing so that he may take in more oxygen. It usually results from the tremendous emotional tension or even anxiety.
Trapped Gases-Tooth Pain
When the cavities go untreated when the pulp get exposed, it may lead to much pain at the altitude. The toothache sometimes vanishes at the same particular elevation if observed on the ascent. Gasses may also get attracted in the tooth at the elevation in abscesses.
Confined Gasses-Stomach and Intestines
In the aeronautics of above 25000 feet, the gasses may lead to serious pain, limits the blood pressure and finally shock to the individuals involved. Whenever the barometric pressure goes down, the partial pressures of the gasses in an individual’s body in the body fluid also diminishes. As a result, the escaping gasses will lead to decomposition sickness.
The physical, as well as the mental flight effects not only on the crew but also on the passengers, has been a great concern in the aviation industry. These people are exposed to various atmospheric changes because of the unpressurized cabins as well as the unacclimatized aircraft cabins. It is, therefore, essential to pay attention to the changes and symptoms that are to be expected in the case of these changes. During the fall of the atmospheric pressure, which leads to the reduction of oxygen partial pressure, hypoxia occurs. Hypoxia is also heightened by increased stress as well performing too much on a cognitive activity. The physical and the mental body of human body changes and becomes highlighted when it is exposed to extreme temperatures and atmospheres. This stress makes all body functions to be altered. The highly affected areas of the body are the respiratory system and the GI tract. Imbalance in the functioning of the body may lead to nausea and vomiting.
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