OBSTRUCTIVE LUNG DISEASE [Mucociliary Clearance]

                 OBSTRUCTIVE LUNG DISEASE[Mucociliary Clearance]

        Obstructive lung diseases are the second (after cardiovascular diseases) leading cause of death in the adult population in India. Obstructive lung disease refers to a group of disease  refers to a group of diseases that share a common feature-difficulty in expelling air from the lungs.

    *Asthma

    *Chronic bronchitis

    *Emphysema

         All the three disorders have an increased airway resistance, but caused by a different mechanism in each case. However, often there is an overlap. Old cases of bronchial asthma, some element of emphysema develops. In chronic bronchitis, some element of bronchospasm is commonly present. Chronic bronchitis and emphysema are considered a spectrum of a chronic obstructive pulmonary disease (COPD) with some patients showing dominantly bronchitis, while others show dominantly emphysema.

     In bronchial asthma, chronic bronchitis and emphysema, the common factor is increased airway resistance. Pathogenesis and pathophysiology of obstructive lung disease can be explained only if the reader is families with the role of mucociliary clearance in respiratory mucosa and physiology of airway resistance.

Mucociliary Clearance

     From trachea down to the terminal bronchioles, the respiratory mucosa is characterized by the presence of cilia, and submucosal mucous glands. The cilia are covered with a blanket of mucus, which traps any incoming particle greater than 5 neu size. The ciliary movement of adjacent cells is so coordinated that it produces waves of ciliay motions from distal to the proximal parts of tracheo-bronchial tree.

 As a result, mucous blanket on the top of cilia laden with dust particles or bacteria is propelled upwards till it reaches the oropharynx, where it is swallowed or expectorated. Mucociliary clearance is a critical factor in the protection of upper respiratory tract.