Diseases of the Respiratory

System

Infections of the Respiratory tract• Most common entry point for

infections• Upper respiratory tract

–nose, nasal cavity, sinuses, mouth, throat

• Lower respiratory tract –Trachea, bronchi, bronchioles,

and alveoli in the lungs

Fig. 21.1a

Clearance of particles and organisms from the respiratory tract

Cilia and microvilli move particles up to the throat where they are swallowed.

Alveolar macrophages migrate and engulf particles and bacteria in the alveoli deep in the lungs.

Protective Mechanisms

Other Protective Mechanisms

• Nasal hair• Mucus• Involuntary responses (coughing)• Immune cells • Strengthening the respiratory system through

exercise helps to strengthen the muscles of the body including the heart and diaphragm.

• Vigorous activities can increase lung capacity and help your body use oxygen more effectively.

Common Disorders of the Respiratory System

Common Cold- coughing, sneezing and sore throat. A cold can be caused by many different things such as different viruses and bacterial infections of the lining in the nose and throat.

Sinusitis- caused by viruses or bacteria in which the sinuses become swollen and irritated. The sinuses provide a moist air space around the nose, when they become inflammed you may notice a change in your voice. It is often by a stuffy, runny nose, pain or swelling in the eyes and cheekbones and pressure in the head

Strep Throat

• Fever• Tonsillitis• Enlarged lymph

nodes• Middle-ear

infection

• Influenza- also called the flu, is a viral infection of the upper respiratory tract. It can develop into pneumonia, which is a serious infection of the lungs.

Bacterial PneumoniaBacterial, viral or fungal infection can cause

Inflammation of the lung with fluid filled alveoli

Bacterial PneumoniaStreptococcus pneumoniae• 2/3 of all pneumonia• Risk Factors- old age, season, underlying

viral infection, diabetes, alcohol and narcotic use

• Variable capsular antigen• Purified component (capsule) vaccine

Others that cause pneumonia:Mycoplasma pneumoniaeLegionella pneumophila

Asthma• Description- Chronic disorder of the

respiratory tract which cause the airways to be narrowed. The condition can be life threatening if untreated.

• Causes- pollution exposure, cigarette smoke, extremely cold air, drugs and infections (viruses/bacteria)

• Treatment- no real cure, controlling the condition is best. For example, a “puffer”, which helps the airways expand.

Bronchitis• Description- when

bronchioles or the airways that connect the alveoli and the trachea become irritated or infected and swell to produce excess mucus.

• Symptoms- wheezing, coughing, difficulty breathing, fevers, chills.

• Causes- exposure to pollutants, cigarette smoke, virus, bacteria, harsh chemicals…

• Treatments- If the case is bacterial a person can take antibiotics, if it is viral then they just have to wait it out and get lots of rest, aspirin and ibuprofen can help aid in the flu like symptoms associated with the illness, a cool vaporizer or humidifier can help alleviate bronchial irritation.

Tuberculosis• Description- Is a bacterial infection caused

by mycobacterium tuberculosis. The disease can be spread person to person when breathing in particles of infected air.

• Symptoms- The bacteria gets in the lungs and causes an infection, coughing up mucus, weight loss, fever, chest pains…

Tuberculosis• Primary

– Lung tubercles, caseous, tuberculin skin reaction

• Secondary (reactivation)– Consumption: Coughing and chronic

weight loss• Dissemination

– Extrapulmonary TB (lymph nodes, kidneys, bones, genital tract, brain, meninges)

Tuberculosis

Treatment- requires long antibiotic treatment with “cocktail” of antibiotics because

of the resistance that develops.

Emphysema• Description- means over

inflated lungs• Cause- occurs when cilia

lining the airways is damaged. Since they no longer filter and channel particles, the bronchioles become clogged and less air reaches the alveoli. Air pressure builds up causing the lungs to appear inflated. The pressure eventually tears the walls of the alveoli.

Symptoms- breath and heart rate increase, body becomes stressed and fatigued.

Treatment- bronchodilators, corticosteroids, oxygen and antibiotics.