this ppt gives information about COPD , Asthma(the respiratory disease)As stated before, diseases of the heart affect the lungs and diseases of the lungs affect the heart. This is because of the peculiar characteristics of pulmonary vasculature. The pressure in the pulmonary arteries is much lower than in the systemic arteries. The pulmonary arterial system is466 SECTION III Systemic Pathology thinner than the systemic arterial system. They are thin elastic vessels which can be easily distinguished from thick-walled bronchial arteries supplying the large airways and the pleura. General diseases of vascular origin occurring in the lungs such as pulmonary oedema, pulmonary congestion, pulmonary embolism and pulmonary infarction, have all been already discussed.