RESPIRATORY SYSTEMRESPIRATORY SYSTEM

The respiratory system generally includes The respiratory system generally includes tubes, such as the bronchi, which are used tubes, such as the bronchi, which are used to carry air to the lungs where gas exchange to carry air to the lungs where gas exchange occurs. The diaphragm, like other muscles occurs. The diaphragm, like other muscles can contract and relax. When someone can contract and relax. When someone inhales, the diaphragm contracts and inhales, the diaphragm contracts and flattens and the chest cavity expands. This flattens and the chest cavity expands. This contraction creates a vacuum that sucks air contraction creates a vacuum that sucks air into the lungs. When exhaling, the into the lungs. When exhaling, the diaphragm relaxes and returns to its diaphragm relaxes and returns to its previous position (dome-like shape) and the previous position (dome-like shape) and the air is expelled from the lungs.air is expelled from the lungs.

PARTS OF THE RESPIRATORY PARTS OF THE RESPIRATORY SYSTEMSYSTEM

Nasal CavityNasal Cavity EpiglottisEpiglottis PharynxPharynx Larynx Larynx Trachea Trachea LungsLungs DiaphragmDiaphragm

NASAL CAVITYNASAL CAVITY

The nostrils or nares are usually locatedThe nostrils or nares are usually located in the in the openings of the nose in some animals. They open openings of the nose in some animals. They open to the outside and let air enter the body.to the outside and let air enter the body.

EPIGLOTTISEPIGLOTTIS The epiglottis is a cartilaginous The epiglottis is a cartilaginous

structure valve that covers the entry of structure valve that covers the entry of the larynx and moves up and down, the larynx and moves up and down, preventing food from entering it and preventing food from entering it and the trachea. It also marks the limit the trachea. It also marks the limit between the oropharynx and the between the oropharynx and the laringopharynx. When breathing, air laringopharynx. When breathing, air passes through the pharynx and goes passes through the pharynx and goes towards the larynx while the epiglottis towards the larynx while the epiglottis remains opened.remains opened.

The epiglottis closes when food gets The epiglottis closes when food gets swallowed and goes down the pharynx. swallowed and goes down the pharynx. This prevents food from obstructing This prevents food from obstructing the larynx.the larynx.

EPIGLOTTISEPIGLOTTIS

The epiglottis guards the entrance of the glottis, the opening between the vocal folds. It is normally pointed upward during breathing with its underside functioning as part of the pharynx, but during swallowing, elevation of the hyoid bone draws the larynx upward; as a result, the epiglottis folds down to a more horizontal position, with its upper side functioning as part of the pharynx. In this manner it prevents food from going into the trachea and instead directs it to the esophagus, which is further down the throat.

PHARYNXPHARYNX The human pharynx is the part of the throat situated The human pharynx is the part of the throat situated

immediately behind the mouth and the nasal cavity, and immediately behind the mouth and the nasal cavity, and above the oesophagus, the larynx, and the trachea. The above the oesophagus, the larynx, and the trachea. The human pharynx is conventionally divided into three human pharynx is conventionally divided into three sections: the nasopharynx , the oropharynx, and the sections: the nasopharynx , the oropharynx, and the laryngopharynx. The pharynx is part of both the digestive laryngopharynx. The pharynx is part of both the digestive and the respiratory systems, and it plays an important role and the respiratory systems, and it plays an important role in vocalisation.in vocalisation.

LARYNXLARYNX The larynx, commonly called the The larynx, commonly called the

voice box, is an organ in the neck voice box, is an organ in the neck of mammals involved in protecting of mammals involved in protecting the trachea against food the trachea against food aspiration, breathing and sound aspiration, breathing and sound production. It manipulates pitch production. It manipulates pitch and volume. The larynx houses the and volume. The larynx houses the vocal folds which are an essential vocal folds which are an essential component of phonation. The component of phonation. The vocal folds are located just below, vocal folds are located just below, where the tract of the pharynx where the tract of the pharynx splits into the trachea and the splits into the trachea and the oesophagus.oesophagus.

TRACHEATRACHEA

The trachea (or windpipe) is the bony tube that connects The trachea (or windpipe) is the bony tube that connects the nose and mouth to the lungs. It is an important part of the nose and mouth to the lungs. It is an important part of the vertebrate respiratory system: when an individual the vertebrate respiratory system: when an individual breathes, air that is caught flows into the lungs through the breathes, air that is caught flows into the lungs through the

windpipe.windpipe.

LUNGSLUNGS

The lungs are the essential breathing organs in many The lungs are the essential breathing organs in many animals, including most tetrapods, a group of fish, and animals, including most tetrapods, a group of fish, and snails. In mammals and more complex life forms, the two snails. In mammals and more complex life forms, the two lungs are located in the chest on either side of the heart. lungs are located in the chest on either side of the heart. Their principal function is to transport oxygen from the Their principal function is to transport oxygen from the air into the bloodstream and release carbon dioxide from air into the bloodstream and release carbon dioxide from the bloodstream into the air. This exchange of gases is the bloodstream into the air. This exchange of gases is accomplished by the mosaic of specialised cells that form accomplished by the mosaic of specialised cells that form millions of tiny, exceptionally thin-walled air sacs called millions of tiny, exceptionally thin-walled air sacs called alveoli.alveoli.

LUNGSLUNGSTo explain the anatomy of the lungs, To explain the anatomy of the lungs, it is necessary to discuss the it is necessary to discuss the passage of air through the mouth to passage of air through the mouth to the alveoli. Once air progresses the alveoli. Once air progresses through the mouth or the nose, it through the mouth or the nose, it travels through the oropharynx, the travels through the oropharynx, the nasopharynx, the larynx, the nasopharynx, the larynx, the trachea, and a progressively trachea, and a progressively subdividing system of bronchi and subdividing system of bronchi and bronchioles, until it finally reaches bronchioles, until it finally reaches the alveoli where the gas exchange the alveoli where the gas exchange of carbon dioxide and oxygen takes of carbon dioxide and oxygen takes place.place.

DIAPHRAGMDIAPHRAGM It is a dome-shaped muscle that It is a dome-shaped muscle that

separates the chest cavity and the separates the chest cavity and the abdominal cavity.abdominal cavity.

It is characteristic of all It is characteristic of all mammals, and in birds it appears mammals, and in birds it appears in a rudimentary way.in a rudimentary way.

INHALATIONINHALATION

Inhalation is initiated by the diaphragm and supported Inhalation is initiated by the diaphragm and supported by the external by the external intercostalintercostal muscles. Normal respirations muscles. Normal respirations are 10 to 18 breaths per minute,are 10 to 18 breaths per minute, with each lasting with each lasting around 2 seconds. During vigorous inhalation (at rates around 2 seconds. During vigorous inhalation (at rates exceeding 35 breaths per minute), or when approaching exceeding 35 breaths per minute), or when approaching respiratory failure, accessory muscles of respiration are respiratory failure, accessory muscles of respiration are recruited for support. These consist of the recruited for support. These consist of the sternocleidomastoid and platysma muscles, and the sternocleidomastoid and platysma muscles, and the scalene muscles of the neck. Pectoral muscles and scalene muscles of the neck. Pectoral muscles and latissimus dorsi are also accessory muscles.latissimus dorsi are also accessory muscles.

INHALATIONINHALATION

Under normal conditions, the diaphragm is the primary Under normal conditions, the diaphragm is the primary driver of inhalation. When the diaphragm contracts, the driver of inhalation. When the diaphragm contracts, the ribcage expands and the contents of the abdomen are ribcage expands and the contents of the abdomen are moved downward. This results in a larger thoracic volume moved downward. This results in a larger thoracic volume and negative pressure (with respect to atmospheric and negative pressure (with respect to atmospheric pressure) inside the thorax. As the pressure in the chest pressure) inside the thorax. As the pressure in the chest falls, air goes into the conducting zone. Here, the air is falls, air goes into the conducting zone. Here, the air is filtered, warmed, and humidified as it flows to the lungs.filtered, warmed, and humidified as it flows to the lungs.

During forced inhalation, as when taking a deep breath, During forced inhalation, as when taking a deep breath, the external intercostal muscles and accessory muscles aid the external intercostal muscles and accessory muscles aid in further expanding the thoracic cavity.in further expanding the thoracic cavity.

EXHALATIONEXHALATION

Exhalation is generally a passive process; however, Exhalation is generally a passive process; however, active or active or forcedforced exhalation is achieved by the exhalation is achieved by the abdominal and the internal intercostal muscles. During abdominal and the internal intercostal muscles. During this process air is forced or this process air is forced or exhaledexhaled out. out.

The lungs have a natural elasticity: as they recoil from The lungs have a natural elasticity: as they recoil from the stretch of inhalation, air flows back out until the the stretch of inhalation, air flows back out until the pressures in the chest and the atmosphere reach pressures in the chest and the atmosphere reach equilibrium.equilibrium.

During forced exhalation, as when blowing out a During forced exhalation, as when blowing out a candle, expiratory muscles including the abdominal candle, expiratory muscles including the abdominal muscles and internal intercostal muscles generate muscles and internal intercostal muscles generate abdominal and thoracic pressure, which forces air out abdominal and thoracic pressure, which forces air out of the lungs.of the lungs.

Exercise regularly, this helps to improve the circulation of the blood.Exercise regularly, this helps to improve the circulation of the blood. Eat a well balanced diet.Eat a well balanced diet. Eat vegetables, especially green vegetables.Eat vegetables, especially green vegetables. Avoid eating too much saturated fats. Use beneficial fats and oils.Avoid eating too much saturated fats. Use beneficial fats and oils. Maintain a healthy weight.Maintain a healthy weight. Live in a clean environment.Live in a clean environment. Avoid smoking cigarettes and second hand smoke. Smoking increases the risk of stroke Avoid smoking cigarettes and second hand smoke. Smoking increases the risk of stroke

and coronary heart disease.and coronary heart disease. Have a positive outlook in life.Have a positive outlook in life. Try to reduce stress and tension.Try to reduce stress and tension. Avoid high blood pressure because this can cause heart failure and strokeAvoid high blood pressure because this can cause heart failure and stroke..

HEALTHY HABITS FOR CARING HEALTHY HABITS FOR CARING FOR OUR RESPIRATORY SYSTEMFOR OUR RESPIRATORY SYSTEM

DISEASES OF THE DISEASES OF THE RESPIRATORY SYSTEMRESPIRATORY SYSTEM

Respiratory diseases can be classified in many different ways: Respiratory diseases can be classified in many different ways: by the organ involved, by the pattern of symptoms or by the by the organ involved, by the pattern of symptoms or by the cause of the disease. The main thing is to always be careful cause of the disease. The main thing is to always be careful around food because some foods can cause allergic reactions around food because some foods can cause allergic reactions and incite breathing difficulties. Some common examples and incite breathing difficulties. Some common examples include seafood (like prawns), some fatty fish, radish, arrow include seafood (like prawns), some fatty fish, radish, arrow root, fish fingers, lemon, dhal, peanuts (dry fruits in general), root, fish fingers, lemon, dhal, peanuts (dry fruits in general), water content spinach, curd, bananas, grapes, pomegranates, water content spinach, curd, bananas, grapes, pomegranates, berries, custard apple, ice creams, etc. In the summer, bad berries, custard apple, ice creams, etc. In the summer, bad weather conditions mean sandy and dusty weather or for some weather conditions mean sandy and dusty weather or for some people, bad weather may be affect them in winter also.people, bad weather may be affect them in winter also.

INFLAMATORY LUNG DISEASEINFLAMATORY LUNG DISEASE

Inflammatory lung disease is also called Chronic Inflammatory lung disease is also called Chronic Obstructive Pulmonary Disease (COPD) and includes a Obstructive Pulmonary Disease (COPD) and includes a wide range of inflammatory lung ailments. These wide range of inflammatory lung ailments. These ailments include asthma, emphysema and chronic ailments include asthma, emphysema and chronic bronchitis. In many cases, the lungs are chronically bronchitis. In many cases, the lungs are chronically inflamed, making it difficult to breathe and placing inflamed, making it difficult to breathe and placing strain on the heart. Individuals with inflammatory lung strain on the heart. Individuals with inflammatory lung disease may find it difficult to engage in exercise or disease may find it difficult to engage in exercise or activities that require heavy breathing. COPD is an activities that require heavy breathing. COPD is an illness that is gaining in frequency as pollution in our illness that is gaining in frequency as pollution in our air increases.air increases.

ASTHMAASTHMA

AsthmaAsthma is a common chronic inflammatory disease of the airways is a common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath.coughing, chest tightness, and shortness of breath.

Treatment of acute symptoms is usually with an inhaled short-acting Treatment of acute symptoms is usually with an inhaled short-acting beta-2 agonist . Symptoms can be prevented by avoiding triggers, such beta-2 agonist . Symptoms can be prevented by avoiding triggers, such as allergens and irritants, and by inhaling corticosteroids. Leukotriene as allergens and irritants, and by inhaling corticosteroids. Leukotriene antagonists are less effective than corticosteroids and thus less antagonists are less effective than corticosteroids and thus less preferred.preferred.

The prevalence of asthma has increased significantly since the 1970s. The prevalence of asthma has increased significantly since the 1970s. As of 2009, 300 million people were affected worldwide. In 2009 As of 2009, 300 million people were affected worldwide. In 2009 asthma caused 250,000 deaths globally. Despite this, with proper asthma caused 250,000 deaths globally. Despite this, with proper control of asthma with step down therapy, prognosis is generally good.control of asthma with step down therapy, prognosis is generally good.

RESPIRATORY TRACT RESPIRATORY TRACT INFECTIONINFECTION

Respiratory tract infections affect the nose, the throat, and the Respiratory tract infections affect the nose, the throat, and the airways, and may be caused by any of several different viruses. airways, and may be caused by any of several different viruses.

Common respiratory tract infections include the common cold and Common respiratory tract infections include the common cold and influenza (flu). influenza (flu).

Typical symptoms include nasal congestion, a runny nose, Typical symptoms include nasal congestion, a runny nose, scratchy throat, cough, and irritability. scratchy throat, cough, and irritability.

The diagnosis is based on symptoms.The diagnosis is based on symptoms. Good hygiene is the best way to prevent these infections, and Good hygiene is the best way to prevent these infections, and

routine vaccination can prevent influenza.routine vaccination can prevent influenza. Treatment aims to relieve symptoms (palliative effect).Treatment aims to relieve symptoms (palliative effect). There are two types: Lower and Upper respiratory tract infections.There are two types: Lower and Upper respiratory tract infections.

RESPIRATORY TUMOURSRESPIRATORY TUMOURS

Malignant tumoursMalignant tumours Malignant tumours, or cancers of the respiratory system, Malignant tumours, or cancers of the respiratory system,

particularly lung cancers, are a major health problem responsible particularly lung cancers, are a major health problem responsible for 15% of all cancer diagnoses and 29% of all cancer deaths. The for 15% of all cancer diagnoses and 29% of all cancer deaths. The majority of respiratory system cancers are attributable to smoking majority of respiratory system cancers are attributable to smoking tobacco.tobacco.

In addition, since many cancers spread via the bloodstream and the In addition, since many cancers spread via the bloodstream and the entire cardiac output passes through the lungs, it is common for entire cardiac output passes through the lungs, it is common for cancer metastases to occur within the lung. Breast cancer may cancer metastases to occur within the lung. Breast cancer may invade directly through local spread, and through lymph node invade directly through local spread, and through lymph node metastases. After metastasis to the liver, colon cancer frequently metastases. After metastasis to the liver, colon cancer frequently metastasizes to the lung. Prostate cancer, germ cell cancer and metastasizes to the lung. Prostate cancer, germ cell cancer and renal cell carcinoma may also metastasize to the lung.renal cell carcinoma may also metastasize to the lung.

Treatment of respiratory system cancer depends on the type of Treatment of respiratory system cancer depends on the type of cancer. Surgery , chemotherapy and radiotherapy are all used. cancer. Surgery , chemotherapy and radiotherapy are all used. The chance of surviving lung cancer depends on the cancer The chance of surviving lung cancer depends on the cancer stage at the time the cancer is diagnosed and is only about 14-stage at the time the cancer is diagnosed and is only about 14-17% overall. In the case of metastases to the lung, treatment can 17% overall. In the case of metastases to the lung, treatment can occasionally be curative but only in certain, rare circumstances.occasionally be curative but only in certain, rare circumstances.

Benign tumoursBenign tumours Benign tumours are relatively rare causes of respiratory disease. Examples of Benign tumours are relatively rare causes of respiratory disease. Examples of

benign tumours are:benign tumours are: Pulmonary hamartoma.Pulmonary hamartoma. Congenital malformations such as pulmonary sequestration and congenital Congenital malformations such as pulmonary sequestration and congenital

cystic adenomatoid malformation.cystic adenomatoid malformation.

PLEURAL CAVITY DISEASESPLEURAL CAVITY DISEASES

Pleural cavity diseases include emphysema and mesothelioma which are Pleural cavity diseases include emphysema and mesothelioma which are mentioned above.mentioned above.

A collection of fluid in the pleural cavity is known as a pleural effusion. A collection of fluid in the pleural cavity is known as a pleural effusion. This may be due to fluid shifting from the bloodstream into the pleural This may be due to fluid shifting from the bloodstream into the pleural cavity due to conditions such as congestive heart failure and cirrhosis. It cavity due to conditions such as congestive heart failure and cirrhosis. It may also be due to inflammation of the pleura itself as can occur with may also be due to inflammation of the pleura itself as can occur with infection, pulmonary embolus, tuberculosis, mesothelioma and other infection, pulmonary embolus, tuberculosis, mesothelioma and other conditions.conditions.

A pneumothorax is a hole in the pleura covering the lung, allowing air in A pneumothorax is a hole in the pleura covering the lung, allowing air in the lung to escape into the pleural cavity. The affected lung “collapses” the lung to escape into the pleural cavity. The affected lung “collapses” like a deflated balloon. A tension pneumothorax is a particularly severe like a deflated balloon. A tension pneumothorax is a particularly severe form of this condition where the air in the pleural cavity cannot escape, so form of this condition where the air in the pleural cavity cannot escape, so the pneumothorax keeps getting bigger until it compresses the heart and the pneumothorax keeps getting bigger until it compresses the heart and blood vessels, leading to a life threatening situation.blood vessels, leading to a life threatening situation.

PULMONAR VASCULAR PULMONAR VASCULAR DISEASEDISEASE

Pulmonary vascular diseases are conditions that affect Pulmonary vascular diseases are conditions that affect the pulmonary circulation.the pulmonary circulation.

Pulmonary embolism, a blood clot that forms in a Pulmonary embolism, a blood clot that forms in a vein, breaks free, travels through the heart and lodges vein, breaks free, travels through the heart and lodges in the lungs. Large pulmonary emboli are fatal, in the lungs. Large pulmonary emboli are fatal, causing sudden death. A number of other substances causing sudden death. A number of other substances can also can also clogclog the lungs but they are much more rare: the lungs but they are much more rare: fat embolism, amniotic fluid embolism , air embolism fat embolism, amniotic fluid embolism , air embolism (iatrogenic - caused by invasive medical procedures).(iatrogenic - caused by invasive medical procedures).

Pulmonary arterial hypertension: elevated pressure in Pulmonary arterial hypertension: elevated pressure in the pulmonary arteries. It is most commonlythe pulmonary arteries. It is most commonly idiopathic idiopathic (i.e. of unknown cause) but it can be due to the effects (i.e. of unknown cause) but it can be due to the effects of another disease, particularly COPD. This can lead to of another disease, particularly COPD. This can lead to a strain on the right side of the heart, a condition a strain on the right side of the heart, a condition known as known as cor pulmonalecor pulmonale..

Pulmonary edema: leakage of fluid from capillaries of Pulmonary edema: leakage of fluid from capillaries of the lung into the alveoli (or air spaces). It is usually the lung into the alveoli (or air spaces). It is usually due to congestive heart failure.due to congestive heart failure.

Pulmonary hemorrhage: inflammation and damage to Pulmonary hemorrhage: inflammation and damage to capillaries in the lung resulting in blood leaking into capillaries in the lung resulting in blood leaking into the alveoli. This may cause blood to be coughed up. A the alveoli. This may cause blood to be coughed up. A pulmonary hemorrhage can be due to auto-immune pulmonary hemorrhage can be due to auto-immune disorders such as Wegener's Granulomatosis and disorders such as Wegener's Granulomatosis and Goodpasture's syndrome.Goodpasture's syndrome.