When irritants are inhaled, they result into swellings of the cells within the respiratory tract (Barnes, 2002 p.52). These cells are then activated to initiate an inflammatory process thus triggers the release of other mediators for inflammatory process like the interleukins, tumour necrosis factor alpha, matrix-metalloproteinase, fibrinogen, interferon gamma and C-reactive protein (Steurer-Stey et al, 2012 p.367). These mediators are responsible for the sustained inflammation process which results to the severe damage to the tissues as well as many other systematic systems. The inflammation sustained inflammation of the tissues of the respiratory system results into changes in the structure of the lungs which further lead to the limitation of the airflow.
The inflammatory response associated with COPD is as a result into the remodelling of COPD thus result into the narrowing of the airways. According to Barnes (2002 p.84), three main factors are responsible for these structural changes namely. accumulation of scar tissue as a result of damage to the airways, peribronchial fibrosis as well as the over multiplication of the epithelial cells within the lining of the airways. These structural changes results into the loss of elasticity of the lung tissue and destruction of parenchyma. Alveoli is also affected because the structures feeding and supporting the alveoli are also destroyed leading to a condition referred to as emphysema. This is the most dangerous process of pathology of COPD since it results into the collapse of the small airways such as alveoli. This is very dangerous since it impedes the flow of air as well as trapping air within the lungs thus reducing lung capacity as compared to normal individuals.
The other change that occurs as a result of COPD is the dysfunction of the mucociliary.