Essay Example on Morphology of the tissue

Morphology of the tissue 25 300 At low magnification the sample appears to be lung tissue due to the presence of air sacs This is confirmed at a higher magnification as there are visible alveolar sacs however these appear to be atypical In the absence of disease alveoli are surrounded by a layer of squamous epithelial cells However in this sample there appears to be hyperplasia of the alveoli epithelium This abnormal epithelial cell growth is a clear sign of disease A vast vascular system is identifiable by many circular clear spaces filled with erythrocytes Smooth muscle cells are the prominent cell type visible in the lung structure There are signs of fibrosis demonstrated by the thicker areas of pale pink stained tissue seen This fibrosis is widespread across the sample suggesting extensive tissue damage The fibrosis has caused a honeycomb appearance Infiltration of lymphocytes neutrophils and macrophages are seen near areas of fibrosis suggesting ongoing chronic inflammation with signs of both long term and short term inflammation visible Across the sample the alveolar macrophages can be seen engulfing the brown fibres Brown and black fibres are visible in the H E stain suggesting inhalation of a foreign substance 

The Perls stain confirms the presence of iron in the ferric state surrounding the brown fibres seen in the H E stain The presence of iron infers that they are ferruginous bodies This combined with the segmented body shape and translucent centre of the fibres allows us to identify the fibres as asbestos fibres The black fibres are most likely inhaled carbon particles Disease process and cellular mechanisms involved 25 300 Fibres are inhaled and enter the respiratory tract Exposure to these fibres causes the accumulation of alveolar macrophages proliferation of fibroblasts and deposition of collagen This fibrosis occurs in the alveolar ducts and bronchiole walls Liu Cheresh and Kamp 2013 The fibres are taken into the interstitium predominantly by Type 1 alveolar epithelial cells where the fibres are mostly cleared by macrophages Apoptosis is induced by the fibres in the macrophages The macrophages secrete cytokines and other chemical mediators starting the inflammatory process Extensive injury to the Type 1 alveolar epithelial cells occurs through intrinsic cell apoptosis induced by the foreign fibres Izumi and Morimoto 2014 

The phagocytosis of the fibres by macrophages causes the release of growth factors including platelet derived growth factor and transforming growth factor β TGF β These growth factors initiate the process of fibrosis Cytokines including interleukin 1 β IL 1 β are also released by the inflammatory cells These cytokines promote the deposition of collagen Liu Cheresh and Kamp 2013 The release of reactive oxygen species ROS is also initiated in the inflammatory response in response to the foreign fibres It has been found that this oxidative stress can promote the inflammation and fibrosis already occurring in the responding tissue Izumi and Morimoto 2014 Origins and related pathology of the substance demonstrated by the Perls stain 20 230 The Perls stain shows the ferric state iron coated asbestos bodies stained blue surrounded by black inhaled carbon particles The presence of asbestos in the lungs is most likely caused through inhalation of the fibres through long term exposure These fibres can cause both acute and chronic inflammation in the respiratory tract Izumi and Morimoto 2014 The severity of lung fibrosis and inflammation is dose dependent to asbestos exposure American Thoracic Society 2004 If the fibres are not removed quickly they can be coated in ferric state iron to create an asbestos body These are the blue stained bodies visible in the Perls stain American Thoracic Society 2004 If the fibres migrate into the pleural lining the pleura will become inflamed causing the formation of pleural plaques 

This accumulation of asbestos fibres and the resulting inflammation and fibrosis is known as Asbestosis Asbestosis belongs to a group of lung disease caused by particle inhalation called pneumoconiosis The pathological characteristics of Asbestosis are the presence of asbestos bodies accompanied by interstitial fibrosis Vaccari et al 2015 Asbestosis is an occupational exposure disease commonly contracted in workers that had prolonged exposure to asbestos in workplaces It is also seen in those who lived near factories that produced asbestos Izumi and Morimoto 2014 The fibrosis caused by asbestosis reduces the lungs elasticity Asbestosis increases the risk of asbestos related malignancies specifically mesothelioma cancer of the pleura Other ways the substance could be detected demonstrated 15 170 Many diffuse interstitial lung diseases have the same clinical presentations including asbestosis Asbestosis resembles idiopathic pulmonary fibrosis amongst other pneumoconiosis Attanoos and Gibbs 2013 Lung function tests such as spirometry are completed as pulmonary fibrosis will restrict lung capacity and can distinguish this from obstructive lung disease such as asthma X rays and CT scans are used to check for fibrosis and pleural plaque formation To confirm that the fibres are asbestos a sample should be analysed by electron microscopy as the resolution of light microscopy is not high enough to detect the single asbestos fibres only the asbestos bodies Popper 2017 Mineral analysis is used to confirm the content of the fibre Attanoos and Gibbs 2013