22.- RESPIRATORY SYSTEM

 22.- RESPIRATORY SYSTEM

The primary function of the respiratory system is to supply the blood with oxygen in order for

the blood to deliver oxygen to all parts of the body. The respiratory system does this through breathing. When we breathe, we inhale oxygen and exhale carbon dioxide. This exchange of gases is the respiratory system's means of getting oxygen to the blood.

Respiration is achieved through the mouth, nose, trachea, lungs, and diaphragm. Oxygen enters the respiratory system through the mouth and the nose. The oxygen then passes through the larynx (where speech sounds are produced) and the trachea which is a tube that enters the chest cavity. In the chest cavity, the trachea splits into two smaller tubes called the bronchi. Each bronchus then divides again forming the bronchial tubes. The bronchial tubes lead directly into the lungs where they divide into many smaller tubes which connect to tiny sacs called alveoli. The average adult's lungs contain about 600 million of these spongy, air-filled sacs that are surrounded by capillaries. The inhaled oxygen passes into the alveoli and then diffuses through the capillaries into the arterial blood. Meanwhile, the waste-rich blood from the veins releases

its carbon dioxide into the alveoli. The carbon dioxide follows the same path out of the lungs when you exhale.

The diaphragm's job is to help pump the carbon dioxide out of the lungs and pull the oxygen into the lungs. The diaphragm is a sheet of muscles that lies across the bottom of the chest cavity. As the diaphragm contracts and relaxes, breathing takes place. When the diaphragm contracts, oxygen is pulled into the lungs. When the diaphragm relaxes, carbon dioxide is pumped out of the lungs.

DISORDERS:

The respiratory system controls breathing which involves the transfer of fresh oxygen to the lungs then bloodstream when breathing in and the removal of carbon dioxide from the lungs when breathing out. Disorders and diseases associated with the lungs essentially restrict or impair the ability to breathe.

There are various disorders of the respiratory system—some conditions, such as asthma, may only affect a person mildly whilst other conditions, such as cystic fibrosis, can be life threatening.

TUBERCULOSIS:

 Tuberculosis (TB) is an infection, primarily in the lungs (a pneumonia), caused by bacteria called Mycobacterium tuberculosis. It is spread usually from person to person by breathing infected air during close contact.

 TB can remain in an inactive (dormant) state for years without causing symptoms or spreading to

other people.

 When the immune system of a patient with dormant TB is weakened, the TB can become active (reactivate) and cause infection in the lungs or other parts of the body.

 The risk factors for acquiring TB include close-contact situations, alcohol and IV drug abuse, and certain diseases (for example, diabetes, cancer, and HIV) and occupations (for example, health-care workers).

 The most common symptoms and signs of TB are fatigue, fever, weight loss, coughing, and night sweats.

 The diagnosis of TB involves skin tests, chest X-rays, sputum analysis (smear and culture), and PCR tests to detect the genetic material of the causative bacteria.

 Inactive tuberculosis may be treated with an antibiotic, isoniazid (INH), to prevent the TB infection from becoming active.

 Active TB is treated, usually successfully, with INH in combination with one or more of several drugs, including rifampin (Rifadin), ethambutol (Myambutol), pyrazinamide, and streptomycin.

 Drug-resistant TB is a serious, as yet unsolved, public-health problem, especially in Southeast Asia, the countries of the former Soviet Union, Africa, and in prison populations. Poor patient compliance, lack of detection of resistant strains, and unavailable therapy are key reasons for the development of drug-resistant TB.

 The occurrence of HIV has been responsible for an increased frequency of tuberculosis. Control of HIV in the future, however, should substantially decrease the frequency of TB.

CYSTIC FIBROSIS:

Cystic fibrosis is a genetic condition affecting predominantly the lungs and pancreas by blocking them with thick mucus. It can impact on lung function, food absorption potentially resulting in malnutrition

and other complications. Mature aged people with cystic fibrosis can also develop osteoporosis, reduced liver function and diabetes due to deficient insulin production as a result of food absorption problems.

Symptoms and characteristics:

• frequent visits to the toilet
• persistent cough, particularly with physical effort
• recurrent chest infections
• poor appetite
• salt loss in hot weather which may produce weakness
• some difficulty in breathing or wheezing with physical effort
• tiredness, lethargy or an impaired exercise ability.

ASTHMA

Asthma occurs when the lung’s air passages narrow, restricting airflow and making it hard to breathe.

The air passages of people with asthma are particularly sensitive and can become swollen and inflamed. This leads to an increased tightening of the muscles around the airways and increased mucus production as well as wheezing, coughing and chest tightness.

There are many asthma triggers and these differ amongst individuals. An asthma attack may be triggered by the inhalation or exposure to allergens—including those from pets, dust mites, moulds and pollens. Alternatively, an attack may be triggered by:

• respiratory infections
• exercise
• cold air
• stress
• food/drug allergies
• cigarette smoke
• other pollutants.

Symptoms and characteristics:

Asthma is a condition that comes and goes and most people with asthma will have an occasional 'attack', while a few people will have symptoms every day.

People experience asthma differently—some have periodic wheezing attacks separated by symptom-free periods, while others have chronic shortness of breath or cough. Asthma symptoms can last minutes to days and can become dangerous if the airflow becomes severely restricted.

Workplace solutions and adjustments:

Asthma cannot be cured but can be well controlled with appropriate medication/treatment and proper

management. Some ideas to assist with management of asthma in the workplace include:

• identification of any known asthma triggers within the workplace to allow for effective management
• if asthma is triggered by exercise or exertion provide less physically strenuous duties in the workplace when symptoms present
• provision of flexible work conditions including breaks to inhale medication and rest time to assist in effectively managing symptoms at work
• reduction of airborne pollutants, chemical vapours and dust within the workplace
• ensure adequate and well maintained ventilation
• ensuring colleagues are educated regarding asthma and emergency first aid procedures if case required within the workplace.

PNEUMOCONIOSIS:

Pneumoconiosis is an occupational lung disease and a restrictive lung disease caused by the inhalation

of dust, often in mines.

Types

Depending upon the type of dust, the disease is given different names:

• Coalworker's pneumoconiosis (also known as "miner's lung", "black lung" or anthracosis) - coal, carbon
• Asbestosis - asbestos
• Silicosis (also known as "grinder's disease" or Potter's rot) - silica
• Bauxite fibrosis - bauxite
• Berylliosis - beryllium
• Siderosis - iron
• Byssinosis - cotton
• Silicosiderosis - mixed dust containing silica and iron

Labrador Lung (found in miners in Labrador, Canada) - mixed dust containing iron, silica and anthophyllite, a type of asbestos.

Diagnosis

Positive indications on patient assessment:

• Shortness of breath
• Chest X-ray may show a characteristic patchy, subpleural, bibasilar interstitial infiltrates or small cystic radiolucencies called honeycombing

Pneumoconiosis in combination with multiple pulmonary rheumatoid nodules in rheumatoid arthritis patients is known as Caplan's syndrome