CHRONIC PULMONARY EMPHYSEMA Airway obstruction disease Extensive alveolar destruction Trapping of excess air in lungs Obstruction Destruction Etiological factor Long term smoking Pathological changes in the lungs Chronic infection due to irritant smoke a. (partial paralysis of the cilia of the respiratory epithelium by the nicitine effects. mucus retention b. Stimulation of excess mucus c. Inhibition of alveolar macrophages Less control of infection

Infection+ Inflammation Of bronchioles Chronic obstruction of airways Obstruction of airwaysDifficult expiration Entrapment of air in alveoli and overstretching % of alveolar wall destruction Lung infection

Abnormalities of emphysema Increased air way resistance leads to increased work of breathing Loss of alveolar walls leads to decreased diffusing capacity Abnormal ventilation perfusion ratioin same lung Physiological shunt Physiological dead space( Va/q)

Loss of alveolar wall No. of pulm. capill Pulm. Vasular resistance Pulmonary hypertension Right heart failure

Over years Hypoxia and hypercapnia death Can cause air hunger

Pulmonary emphysema It is one of the obstructive respiratory diseases in which lung tissue is extensively damaged. This literally means that air is trapped in the lungs. Causes are: Chronic infection caused by inhaling smoke or other irritants.

Infection causes Alveolar macrophages are also inhibited Partial paralysis of the rssp. Epithelium (nicotine). Mucus is not removed Infection causes excess mucous and inflammatory edema causes chronic obstruction of the smaller alveoli This causes entrapment of air in the alveoli leading to overstretching of the alveoli leading to the destruction of 50 – 80 % of the alveolar walls. Abnormalities produced: Bronchial obstruction causing increased airway resistance. The work of breathing is massively increased especially during expiration.

Loss of alveolar walls greatly decreases the diffusion capacity of the lung. Extensively abnormal ventilation-perfusion ratios Loss of alveolar walls causes loss of pulmonary capillaries causing pulmonary hypertension leading to right sided heart failure Hypoxia, hypercapnia.

Tuberclosis Constrictive lung disease; Etiology: tubercle bacilli lead to tissue reaction in lungs lead to 1)Macrophage invasion 2)Walling off of lesion by fibrous tissue leading to tubercle formation which causes further prevention of transmission of tubercle bacilli in lungs of walling off process If untreated in 3% walling off fails Massive destruction of lung tissue Large abcess cavities Late stages= increase fibrous tissue and decrease function of lung tissue.

Results: Increase work of breathing by respiratory membrane Decrease vital capacity Decrease breathing capacity Decrease respiratory membrane surface area Increase thickness of respiratory membrane Decrease pulmonary diffusion capacity Abnormal ventilation perfusion ratio in lungs leading to decrease pulmonary difference of Oxygen and Carbon dioxide.

pneumonia It is an infection of pulmonary parenchyma. Caused by viruses,fungi,and parasites. It may involve primarily the interstetium or alveoli Involvement of entire lobe is called LOBAR PNEUMONIA Involvement of alveoli contiguous to bronchi is called BRONCHOPNEUMONIA

Pneumonia Consolidation of lung occurs i.e, alveoli are filled with blood cells and fluids Pulmonary membrane becomes inflamed and porous so leaking occurs.

Abnormalities of function Early stage; localized pneumonia 1)Decrease total surface area of respiratory membrane 2)Decrease V/Q ratio Result: hypoxemia and hypercapnia