1. DISEASES OF THE LUNG Dr. zameer pasha

2. Anatomy

3. Types of lung diseases: Airway diseases -- These diseases affect the tubes (airways) that carry oxygen and other gases into and out of the lungs. These diseases cause a narrowing or blockage of the airways. They include asthma, emphysema, and chronic bronchitis. People with airway diseases sometimes describe the feeling as "trying to breathe out through a straw." Lung tissue diseases -- These diseases affect the structure of the lung tissue. Scarring or inflammation of the tissue makes the lungs unable to expand fully ("restrictive lung disease"). It also makes the lungs less capable of taking up oxygen (oxygenation) and releasing carbon dioxide. Pulmonary fibrosis and sarcoidosis are examples of lung tissue diseases. People sometimes describe the feeling as "wearing a too-tight sweater or vest" that won't allow them to take a deep breath. Pulmonary circulation diseases -- These diseases affect the blood vessels in the lungs. They are caused by clotting, scarring, or inflammation of the blood vessels. They affect the ability of the lungs to take up oxygen and to release carbon dioxide. These diseases may also affect heart function.

4. Common lung diseases – Asthma Chronic bronchitis COPD (chronic obstructive pulmonary disease) Emphysema Pneumonia Tuberculosis Lung cancer

5. Asthma ◦Asthma is an inflammatory disorder of the airways, which causes attacks of wheezing, shortness of breath, chest tightness and coughing. Common triggers of asthma – Animals (pet hair) Dust Changes in weather (most often cold weather) Chemicals in the air or in food Exercise Pollen Respiratory infections, such as the common cold Strong emotions (stress) Tobacco smoke

6. Emergency symptoms: Bluish color to the lips and face Decreased level of alertness such as severe drowsiness or confusion, during an asthma attack Extreme difficulty breathing Rapid pulse Severe anxiety due to shortness of breath Sweating

7. Atelectasis (collapse) Incomplete expansion of the lungs or collapse of previously inflated lung substance. Types of atelectasis 1.Resorption atelectasis. 2.Compression atelectasis. 3.Contraction atelectasis. Resorption atelectasis Result from complete obstruction of an airway and absorption of entrapped air.

8. Compression atelectasis Results whenever the pleural cavity is partially or completely filled by fluid, blood, tumor or air. Contraction atelectasis. Local or generalized fibrotic changes in pleura or lung preventing full expansion of the lung. Atelectatic lung is prone to develop superimposed infection. It should be treated promptly to prevent hypoxemia.

9. Chronic Obstructive Pulmonary Disease (COPD) A group of conditions characterized by limitation of airflow it is one of the most common lung diseases There are two main forms of COPD: ◦Chronic bronchitis: which involves a long-term cough with mucus ◦Emphysema: which involves destruction of the lungs over time Most people with COPD have a combination of both conditions. Chronic bronchitis: clinically it is defined as a cough with sputum production on most days for 3 months of a year, for 2 consecutive years.

10. Emphysema: Emphysema is an enlargement of the air spaces distal to the terminal bronchioles, with destruction of their walls. Types – ◦Centriacinar: Centrilobular emphysema ◦Panacinar: Panlobular emphysema ◦Paraseptal: Paraseptal emphysema ◦Irregular Causes- ◦Smoking; Occupational exposures; Air pollution; Genetics ; Autoimmune disease One of the most common symptoms of COPD is shortness of breath (dyspnea). a persistent cough, sputum or mucus production, wheezing, chest tightness, and tiredness.

12. Bronchiectasis Chronic necrotizing infection of the bronchi and bronchioles leading to abnormal dilatation of these airways. Clinical course: ◦Sever persistent cough with sputum (mucopurulent, fetid sputum) sometimes with blood. ◦Clubbing of fingers. ◦Rare complications: metastatic brain abscess and amyloidosis.

13. Pneumonia: is defined as acute inflammation of the lung distal to the terminal bronchioles. (respiratory bronchiloes, alveolar ducts, alveolar sacs & alveoli). Types – Based on etiology ◦Bacterial ◦Viral ◦Others – aspiration, hypostatic, lipid. Based on area affected ◦Lobar pneumonia – part of lobe, entire lobe, or two lobes ◦Lobular pneumonia – only terminal bronchiloes and alveoli. ◦Interstitial pneumonia – inflammation confined to interstitial tissues of the lung without any alveolar exudate.

14. Pathologic changes – Lobar,Lobular pneumonia shows patchy areas of red and grey hepatisation, acute bronchiolitis ◦Clinical features: chills, fever, malaise, chest pain, dyspnoea and cough with expectoration.

15. Lung cancer – most common primary cancer of the lung is bronchogenic carcinoma (95%). Lung is also the commonest site for metastasis from carcinomas and sarcomas. Bronchogenic carcinoma – most common tumor in men. Etiology ◦Smoking – quantity, type ◦Atmospheric pollution ◦Occupational cases ◦Dietary factors – contributing factor ◦Genetic

16. Clinical features: Cough Chest pain Dyspnoea Haemoptysis Symptoms due to metastasis. Histologic types: squamous cell carcinoma small cell carcinoma adenocarcinoma large cell carcinoma adenosquamous carcinoma Lung carcinomas spread both by lymphatic and hematogenous pathways.

17. Thank you References: ◦Robbins basic pathology – Kumar et al ◦Essential pathology for dental students – Harsh Mohan