INTRODUCTION
Imagine people around you not breathing, for sure the world will not be normal, so, the human respiratory system plays a crucial role to the survival of human life in the society where communication takes place. Human respiratory involves various mechanisms along with the circulatory system to deliver oxygen from the lungs to the cells and remove carbon dioxide and return it to the lungs to be exhaled. The exchange of oxygen and carbon dioxide between the air, blood and body tissues is known as respiration. It is said that vigorous lungs takes about 1 pint of air for about 12-15 times each minute as the blood in the body passed through the lungs every minute.
Source: (2004). Breathing
MAIN BODY
Breathing
Thus, breathing process consists of two phases: the inspiration phase that allows air to flow into the lungs and the expiration phase that amicably involves gases leaving the lungs. In the inspiration stage, the diaphragm and intercostal muscles contract, allowing air to enter the lungs as in expiration, the inspiration muscles relax forcing gases to flow out of the lungs. Thus, breathing is an automatic process controlled by the respiratory center in the brain. Intercostal muscles around the chest cavity are stimulated by the medulla, causing them to contract and relax. The intercostal muscles increase thoracic volume by raising the top border of the thorax, while the diaphragm increases it by lowering the bottom border of the thorax as it contracts and relaxes, that will draw air into and forces air out of the lungs as the flow of air occurs only when there is a difference in pressure. Air naturally flows from a region of high pressure to one of low pressure, and the bigger the difference in pressure, the faster the flow.
The intercostal muscles are located between the ribs. There are two kinds of intercotal muscles: internal and external. The intercostal muscles are controlled by the medulla. The internal intercostal muscles are located on the inside of the ribs and extend from the front of the ribs, around back and past the bend in the ribs. The external intercostal muscles are located on the outside of the ribs, and wrap around the back of the ribs. The diaphragm is the muscular partition located between the chest cavity and the abdominal cavity. It plays a major role in respiration. During inspiration, the diaphragm descends, the inspiratory muscles contract and the rib cage rises. During expiration, the diaphragm rises, the inspiratory muscles relax and the rib cage descends.
Source: (2004). Breathing
It is believed that various volumes of the pulmonary – the lungs and capacities measure such features regarding the system as the volumes vary with the age and height of the human being.
The Volumes
Total lung capacity (TLC) which is about five litres of air the lungs can hold.
Vital capacity (VC) The maximum volume of air that can be expelled at the normal rate of exhalation after a maximum inspiration
Tidal volume (TV) is the amount of air breathed in or out during normal respiration.
Residual volume (RV) is the amount of air left in the lungs after a maximal exhalation.
Expiratory reserve volume (ERV) is the amount of additional air that can be breathed out after normal expiration.
Inspiratory reserve volume is the additional air that can be inhaled after a normal tidal breath in.
Functional residual capacity (ERV + RV) is the amount of air left in the lungs after a tidal breath out.
Inspiratory capacity (IC) is the volume that can be inhaled after a tidal breath out.
Anatomical dead space is the volume of the airways.
Factors affecting lung volume
Tidal breathing means that air goes into the lungs, the same way that it comes out. The total lung capacity depends on age, weight, sex and the degree of physical activity. Lung capacity is also affected by altitude. A person who was born and lives at sea level will have a smaller lung capacity than a person who spends their life at a high altitude as there is less oxygen in the air so; the lungs gradually expand to process more air.
Source of the above graph: ,
Retrieved from
Gas Exchange within the Lungs
Bronchi, Bronchioles and Alveoli
Source: (2004). Breathing
Bronchi and Bronchioles
The air from the bronchi passes into the smaller airways called the bronchioles, and then into the alveoli. The alveoli are tiny air sacs at the end of the bronchioles. It is within the alveoli where the oxygen from the air enters the blood, and carbon dioxide from the blood enters the lungs.
Alveoli
The blood barrier between the alveolar space and the pulmonary capillaries is very thin to allow for rapid gas exchange. During inspiration, oxygen diffuses through the alveoli walls and the interstitial space, into the blood. Carbon dioxide diffuses in the opposite direction during exhalation. Alveoli are smaller than grains of salt, with approximately 300 million alveoli in each lung. Although alveoli are tiny structures, they have a very large surface area in total for performing efficient gas exchange.
People can say that pulmonary ventilation may arguably be the most important process of respiration, in that, its function is to continually renew the air content within the lungs. Without continual renewal of the air content in the lungs, the oxygen that is available for respiration and energy conversion would be depleted quickly. The conducting zone is the portion of the lungs that aids in the movement of air in and out of the surrounding and sets the initial availability of air to move into the respiratory zone. In the conducting zone, no gas exchange occurs.
The respiratory zone is the portion of the lungs that includes alveoli and capillary plexus and is the site where initial gas exchange between the lungs and blood occurs. In this lesson, we will learn how each of these zones is ventilated and how air moves into the lungs, a negative pressure differential occurs when the diaphragm contracts downward, allowing the lungs to expand with air. The action is known as inspiration. The movement of air from the lungs to the ambient environment is accomplished when a positive pressure differential occurs, as the diaphragm relaxes, increasing the pressure in the lungs and forcing air out of the nose and mouth. The action is known as expiration. The function of the respiratory zone of the lungs is to provide concurrent gas exchange of O2 and CO2 between the lungs and blood. The act of inspiration brings the necessary O2 into the respiratory zone and the act of expiration removes the CO2 from the respiratory zone. The respiratory zone consists of the alveoli and capillary plexus. Each alveolar sac in the lung has contact with the capillary plexus. It is at the junction of the alveoli and capillary plexus where O2 is exchanged from the alveoli to the blood and CO2 is exchanged from the blood to the alveoli. Ventilation acts as the end process to remove carbon dioxide from the body and put it back into the atmosphere in expiration. It is safe to assume that for every liter of inspired ambient air, the O2 content of that air will consist of 209.3 ml of O2.
Tidal Volume and Oxygen Capacity
The volume of air that an individual ventilates in one breath is known as the tidal volume (VT), and maximum VT is limited to an individual’s lung volume. Normal total lung capacities/volumes for the average human are approximately 6 liters for males and 4 liters for females. The lungs however, retain a residual volume (RV) of air necessary to keep the lungs inflated and aid in oxygen transport during the time intervals between breaths. Approximately 20% of the total lung capacity (TLC) consists of the residual volume. This means that the maximal tidal volume (VT) for a male with a 6 L TLC is 4.8 liters: 6 L * 0.8 = 4.8 L Conversely, the maximal tidal volume (VT) for a female with a 4 liter TLC is 3.2 liters: 4 L * 0.8 = 3.2 L and that the greatest amount of O2 available to a male during a single ventilatory cycle (breath) would be: 4.8 L * 0.2093 = 1.004 L O2 The greatest amount of O2 available to a female during a single breath would be: 3.2 L * .2093 = 696.7 ml. If oxygen is necessary for energy conversion in aerobic metabolism, then the same time element must be involved. Therefore, the maximal VT for a single ventilatory cycle depends on the TLC and the RV of the individual.
Ventilatory frequency (f) is the term that describes the number of breaths taken in one minute. As frequency of breaths increase, the rate of air movement in and out of the lungs increases. Ventilatory frequency for most healthy individuals is approximately 12 breaths per minute at rest and can range from 15 breaths per minute for light exercise, up to 60 breaths per minute during all out maximal effort. Minute ventilation for a healthy individual can range from approximately 6 L/min at rest to above 200 L/min during all out maximal effort depending on the lung volume, breathing patterns, and body size of the individual. At this time, it is pointed out that this description of VE is describing the ventilation of the lungs as a whole, meaning, VE incorporates both the conducting zone and the respiratory zone. To determine how VE is affected by breathing patterns.
Alveolar Ventilation and Residual Volume
The respiratory zone is where gas exchange occurs, so we need ventilation of the alveoli for gas exchange. Alveolar ventilation is the movement of air in and out of the alveolar sacs. Residual Volume is the air that keeps the lungs inflated and aids in gas exchange between breaths. A small portion of the RV remains in the alveoli at all times for the purpose of gas exchange between breaths, however, the greater portion of the RV is contained in the anatomical dead space (VD) of the conducting zone.
The air that remains in the VD acts as a buffer by mixing with newly inspired air and protects the alveolar air from severe fluctuations in mixed gas concentrations during inspiration through protecting from severe fluctuations in air concentrations in the alveoli, the VD allows for consistency of blood gas composition during minute ventilation. The incremental graph represents each of the variables at a given percent effort. During incremental work, there would be a linear relation between VE percent efforts. During prolonged submaximal effort, VE is greater than it was at light exercise, but it also reaches a steady state. During incremental exercise, VE seems to have two points during the effort where the slope of the line changes and steady state is never reached and understand that steady state can’t be achieved because the work effort is increasing with time, changes in the slope of the line that represents VE as each breakpoint in magnitude of the slope of VE represents a ventilatory threshold.
Incremental Graph
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The lungs retain a residual volume (RV) of air where the greatest portion of the RV remains in the alveoli at all times for the purpose of gas exchange between breaths. We also learned that a small portion of the RV is contained in the anatomical dead space (VD) and the air in the VD acts as a buffer by mixing with newly inspired air and protects the alveolar air from severe fluctuations in mixed gas concentrations during inspiration. These two points change the dynamics of the mixed air concentrations within the alveoli thereby, changing the partial pressures in the alveolar air.
Residual Volume and Dead Space Volume
Think about the residual volume in the alveoli first. Diffusion at the alveolar-capillary plexus area occurs continuously, during and between both inspiration and expiration. Think about between breath time periods. If diffusion is occurring continuously, then gasses are diffusing in the alveoli even when inspiration or expiration is not occurring. This would mean that the residual volumes gas concentrations are changing due to diffusion during the resting periods between breaths. The mixing effect between the new air and RV has a proportion of gasses such that N is 74.9%, O2 is 13.7%, and CO2 is 5.3%.
Diffusion requires a concentration gradient and we want O2 to diffuse into the blood supply so that we can use the O2 for energy turnover. The blood in the capillary plexus of the lung has a PO2 of 40 mmHg because the pulmonary blood supply returning to the alveoli is deoxygenated due to the use of oxygen for energy turnover in the mitochondria. The concentration of O2 is greater in the alveoli than the pulmonary blood supply as evident by the PO2 differences; oxygen diffuses from the higher PO2 in the alveoli to the lower PO2 in the capillary. As O2 diffuses from the alveoli into the blood, the oxygen concentration in the capillary plexus and pulmonary blood supply increase to a maximum of 104 mmHg due to diffusion. You may have noticed that the authors of your text show in figure 10.10 of your book that PO2 of the arterial blood is 100 mmHg where as we have stated PO2 leaving the lungs is 104 mmHg. The discrepancy between the values is simply explained by the assumption of where PO2 measures are taken after blood leaves the lungs. As the newly oxygenated blood leaves alveoli of the lungs through the pulmonary vein, it maintains a PO2 of 104 mmHg. The blood of the pulmonary vein then mixes with blood from the bronchial artery before it reaches the left side of the heart. The bronchial artery blood is slightly deoxygenated because it is delivering O2 to the bronchial tissue. If you measure the PO2 of the blood before the bronchial artery blood mixes, the PO2 is 104 mmHg. If you measure the PO2 of the blood after the mixing occurs, the blood supply has a PO2 of 100 mmHg.
The oxygen is diffusing into the capillary; the PCO2 levels in the blood are higher than those levels in the alveoli because CO2 is a byproduct of energy turnover. In the alveoli, the PCO2 levels are 40 mmHg compared to 46 mmHg in the pulmonary blood and capillary plexus. Again, since diffusion of a gas always down a concentration gradient, CO2 diffuses from the high concentration in the blood to the lower concentration in the alveoli. The net effect of the diffusion is removal of the CO2 from the blood into the lungs, where pulmonary ventilation will expel the CO2 during expiration. The concentration of O2 is ever decreasing in the muscle and the mitochondria because O2 is being used for energy turnover, causing oxygen to diffuse from the blood to the muscle tissue and from the muscle tissue to the mitochondria. Inversely, CO2 is higher in the mitochondria than the muscle tissue and the venous blood supply because CO2 is a byproduct of energy turnover, causing CO2 to diffuse from the mitochondria to the muscle tissue and then from the muscle tissue into the venous blood supply.
The removal of O2 from the RBC at the tissue site is called oxygen dissociation and is representative of hemoglobin saturation. In other words, as dissociation increases, saturation decreases. The first factor that creates changes in the dissociation of O2 from the hemoglobin is temperature. As temperature increases, oxygen is removed more efficiently. During metabolism, a portion of the energy turnover is released as heat energy in the tissue. This increase in heat allows for easier dissociation of the oxygen in the tissue, thereby aiding in oxygen availability for aerobic energy turnover. The second factor that creates changes in the dissociation of O2 from the hemoglobin is pH or acidity of the tissue. As the pH or acidity increases, oxygen is removed more efficiently from the hemoglobin.
Source: Gas Exchange in Humans
http://www.cdli.ca/~dpower/resp/exchange.htm
External Respiration
When a breath is taken, air passes into the nostrils, through the nasal passages, into the pharynx, through the larynx, down the trachea, into one of the main bronchi, then into smaller broncial tubules, through even smaller broncioles, and into a microscopic air sac called an alveolus. It is here that external respiration occurs as it is the exchange of oxygen and carbon dioxide between the air and the blood in the lungs. Thus, blood enters the lungs through the pulmonary arteries. It then proceeds through arterioles and into the alveolar capillaries. Oxygen and carbon dioxide are exchanged between blood and the air.
Source: Gas Exchange in Humans
http://www.cdli.ca/~dpower/resp/exchange.htm
Internal Respiration
The human body tissues need the oxygen and have to get rid of the carbon dioxide, so the blood carried throughout the body exchanges oxygen and carbon dioxide with the body’s tissues. Internal respiration is the exchange of gasses between the blood in the capillaries and the body’s cells.
Source: The Respiratory System
From:
Gas Exchange and Hemoglobin
Chemical Analysis of the gases that is inhaled and exhaled
Gas Inhaled Gas Exhaled
O2 20.71% 14.6%
CO2 0.04% 4.0%
H2O 1.25% 5.9%
DISORDERS
Lung Cancer
Lung cancer is a disease caused by the rapid growth and division of cells that made up the lungs and under normal circumstances, lung cells reproduce in an orderly fashion to maintain tissue health and to repair injuries. If the tumor is confined to a few cell layers and it does not invade surrounding tissues or organs, it is considered benign.
Source: (2005). Overview: Lung Cancer, What is Lung Cancer
Retrieved at:
Most lung cancers started in the lining of the bronchi, although they can start in other parts of the lung. Lung cancer often takes many years to develop. First, there may be areas of pre-cancerous changes in the lung. Thus, once lung cancer occurs, cancer cells can break away and spread to other parts of the body in a process called metastasis. Lung cancer is a life-threatening disease because it often spreads before it is diagnosed.
Asthma
Asthma is a chronic lung condition which is characterized by difficulty in breathing and people with asthma have extra sensitive airways. The airways react by narrowing or obstructing when they become irritated. This makes it difficult for the air to move in and out.
The obstruction can cause one or a combination of the following symptoms:
Ø wheezing
Ø coughing
Ø shortness of breath
Ø chest tightness
The obstruction is caused by:
Ø Airway inflammation to which the airways in the lungs become swollen and narrow
Ø Bronchoconstriction to which the muscles that encircle the airways tighten
Airway Inflammation
This picture shows the opening of a normal airway on the left. On the right is the picture of an airway which has been exposed to a certain stimulus. It has become inflamed and plugged with mucus, thus making the airway opening considerably smaller and more difficult for air to get through.
Source: (January 20, 2003)
Bronchoconstriction
This picture shows the opening of a normal airway on the left. On the right is the picture of an airway which has been exposed to a certain stimuli. The muscle fibers surrounding the airway have contracted, thus, making the airway opening considerably smaller.
Source: (January 20, 2003)
Bronchitis
Bronchitis may be caused by a virus, bacteria, smoking or the inhalation of chemical pollutants or dust. When the cells of the bronchial-lining tissue get irritated beyond a certain point, the tiny hairs (cilia) within them which normally trap and eliminate pollutants will stop functioning. Consequently, the air passages become clogged by debris and irritation increases. In response, a heavy secretion of mucus develops, which causes the characteristic cough of bronchitis.
Source:
Bronchitis is an inflammation of the lining in the bronchial tubes, the airways that connect the trachea to the lungs. This delicate, mucus-producing lining covers and protects the respiratory system, the organs and tissues involved in breathing. When a person has bronchitis, it may be harder for air to pass in and out of the lungs than it normally would, the tissues become irritated and more mucus is produced. Bronchitis can be acute or chronic.
Chronic bronchitis is most common in smokers. People who have repeated episodes of acute bronchitis sometimes develop the chronic condition while a person with chronic bronchitis has a chronic productive cough. The symptoms of acute bronchitis includes shortness of breath and chest tightness on most days of the month. Acute bronchitis is most often caused by viruses that infects the respiratory tract and attack the bronchial tubes.
Acute bronchitis symptoms may include:
Ø cough that may bring up thick yellow mucus
Ø headache
Ø Infection
Ø generally feeling ill
Ø chills
Ø fever
Ø shortness of breath
Ø soreness or a feeling of tightness in the chest
Ø wheezing
Reviewed by:
Date reviewed: September 2004
Teens Health
Emphysema
Emphysema is a chronic lung disease that can get worse over time and is usually caused by smoking and mean that some of the air sacs in the lungs are damaged, making it hard to breathe.
Emphysema can be caused of:
Cigarette smoking
Most cases of emphysema are caused by cigarette smoking. Cigarette smoke reaches deep into the lungs and causes permanent damage known as Alpha-1 Antitrypsin deficiency. Some people have emphysema because of a rare genetic disorder called Alpha-1 Antitrypsin deficiency. People with Alpha-1 are missing an enzyme that protects their lungs.
Air pollution
There is some evidence that air pollution can contribute to people getting emphysema, especially if the person smokes. Emphysema will get worse if a person continues to smoke and breathes dirty air.
Signs and symptoms of emphysema
Ø Shortness of breath
Ø A barrel-shaped chest
Ø Wheezing
Ø Feeling tired
Ø Losing weight without trying
Pneumonia
Pneumonia is an inflammation or infection of the lungs. The lungs’ air sacs fill with pus, mucus, and other liquids which made it not to function properly. Oxygen cannot reach the blood. If there is insufficient oxygen in the blood, body cells cannot function properly and may die. Lobar pneumonia affects a section (lobe) of a lung. Bronchial pneumonia affects patches throughout both lungs.
Lobar Pneumonia
Bronchial Pneumonia
“Pneumonia” encompasses many different diseases that involve infection or inflammation of the lungs. Pneumonia affects the lobe of the lungs and bronchial pneumonia can affect patches throughout both lungs. Pneumonia is caused by viruses; bacteria and mycoplasmas and by the inhalation of food; liquid; dust; and fungi. Viral pneumonia is less common in normal adults with a fully functioning immune system; however, most pneumonia in the very young is caused by viral infection. The symptoms of viral pneumonia are similar to influenza symptoms and include fever; dry cough; headache; muscle pain; weakness; fever; and increasing breathlessness.
Tuberculosis
Tuberculosis (TB) is an infectious disease caused by bacteria which has a scientific name of Mycobacterium tuberculosis. TB commonly affects the lungs but can also involve most of the organs in the body. Today, tuberculosis usually can be treated successfully with antibiotics. A person can become infected with tuberculosis bacteria when he or she inhales minute particles of infected sputum from the air. The bacteria get into the air when someone who has a tuberculosis lung infection coughs, sneezes, shouts, or spits (which is common in some cultures). People who are nearby can then possibly breathe the bacteria into their lungs. You don’t get TB by just touching the clothes or shaking the hands of someone who is infected. Tuberculosis is spread (transmitted) primarily from person to person during close contact by breathing infected air.
Respiratory Distress Syndrome of the Newborn
Respiratory distress syndrome (RDS) is life threatening lung disorder that commonly affects premature infants. Respiratory distress syndrome results from insufficient levels of surfactant, a foamy fluid substance produced by the body between 34 and 37 weeks of pregnancy. Surfactant is essential for the expansion of the alveoli or air sacs of the lungs. The incidence and severity of RDS are related inversely to the gestational age of the infant. The outcome of RDS has improved in recent years with the increased use of antenatal steroids to improve pulmonary maturity, early postnatal surfactant therapy to replace surfactant deficiency, and gentler techniques of ventilation to minimize damage to the immature lungs. Direct attention to anticipate and minimize the complications and towards preventing premature delivery whenever possible is the strategic goals.
Sudden Infant Death Syndrome (SIDS /cot death)
In a scientific study of SIDS, episodes of cessation of breathing and hypopnea, the abnormally shallow breathing were measured before and after DPT vaccinations. The data clearly shows that vaccination caused an extraordinary increase in episodes where breathing either nearly ceased or stopped completely. SIDS occurs among babies who have suffered a physical insult to their vulnerable bodies. Rather than attempt to duplicate their work or alter public health policy to protect infants, the majority of the medical community’s members chose to protect the interests of vaccine manufacturers. In a recent scientific study of SIDS, episodes of apnea and hypopnea were measured before and after DPT vaccinations. “Cot watch”, a precise breathing monitor was used and computer print-outs were generated (in integrals of the weighted apnea-hypopnea density – WAHD) analyzed. The data clearly shows that vaccination caused an extraordinary increase in episodes where breathing either stopped completely.
Coryza
The common cold may be caused of variety viruses such as rhinoviruses and adenoviruses, influenza viruses. More than 95 rhinovirus serotypes have been discovered in relationship to coryza yet; there is still no effective treatment in orthodox medicine. Not all colds are caused by viruses in the first place. Some acute coryza may have other causes, such as the elimination of waste products, specific allergens or pollution. The incubation period is usually 18 to 48 hour after exposure after which the onset is often rather abrupt. The symptoms often start with a scratchy, itchy, or burning throat, followed by sneezing and varying degrees of malaise.
Influenza
Influenza is an acute viral miasm that affects the respiratory system and produces generalized aches and pain, especially in the limbs and back; malaise; prostration; fever; coryza, headache; with photophobia and retrobulbar aching; and inflamed respiratory mucous membranes. The incubation period is around 48 hours. The symptoms begin with sore throat with substernal burning; nonproductive cough and coryza. The soft palate, posterior hard palate, tonsils and throat become reddened and painful. The eyes water easily and the conjunctiva may be mildly inflamed. Sweating and weakness may continue for weeks. Complications include bronchitis; pneumonia; breathlessness; spitting of blood; pulmonary edema; encephalitis and death.
Pulmonary Embolism
Pulmonary embolism (PE) is an extremely common and highly lethal condition that is a leading cause of death in all age groups. A good clinician actively seeks the diagnosis as soon as any suspicion of PE whatsoever is warranted, because prompt diagnosis and treatment can dramatically reduce the mortality rate and morbidity of the disease. Unfortunately, the diagnosis missed far more often than it is made, because PE often causes only vague and nonspecific symptoms. The most sobering lessons about PE are those obtained from a careful study of the autopsy literature. Deep vein thrombosis (DVT) and PE are much more common than usually realized. Most patients who died of PE have not had any diagnostic workup, nor have received any prophylaxis for the disease. In most cases, the diagnosis has not even been considered, even when classic signs and symptoms are documented in the medical chart.
Pulmonary Oedema
Pulmonary oedema involves the abnormal accumulation of fluid in the interstitial compartment of the lung with or without associated air-space filling. The oedema is due to changes in hydrostatic forces in the capillaries, to increase capillary permeability or to impaired lymphatic drainage. Transudative pulmonary oedema is due to increase hydrostatic pressure or, rarely, due to decrease oncotic pressure across a functioning capillary membrane. Hydrostatic pulmonary oedema can result from cardiogenic or noncardiogenic causes. Cardiogenic pulmonary oedema is a consequence of elevated left-sided pressure which may result from left ventricular dysfunction, mitral valve disease, left a trial disease.
Smoke Inhalation
Smoke inhalation occurs when a person breathe in the products of combustion during a fire. Combustion results from the rapid breakdown of a substance by heat and smoke which is a mixture of heated particles and gases. It is impossible to predict the exact composition of smoke produced by a fire. The products being burned, the temperature of the fire and the amount of oxygen available to the fire all make a difference in the type of smoke produced. Smoke inhalation damages the body by simple lack of oxygen, chemical irritation and chemical asphyxiation. Combustion can simply use up the oxygen near the fire and lead to death when there is no oxygen to breathe. Combustion can result in the formation of chemicals that cause direct injury when they contact your skin and mucous membranes and that the substances disrupt the normal lining of the respiratory tract.
CONCLUSION
Therefore, I conclude that the process of respiration and its essential mechanisms is needed for the survival of human life and that without a healthy respiration, the human body will be weak and is prone to have disorders and or diseases that will cause death to many people due to a fact that they are not aware of their health such as a chain smoker does not know that constant and daily smoking can damage his lungs and may cause himself to have emphysema – that will negatively affect the overall function of the respiratory system that may possibly lead to further diseases and complications. It is very much important to take care of one’s respiratory system because it is the sole pathway to a normal breathing process as the person inhales and exhales the air in his environment and be able to continuously live a normal life, thus, have a healthy life style respectively.
REFERENCES
Credit:ivythesis.typepad.com
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