![]() ![]() seen most commonly along the posterior/anterior margins of the upper lung.(3) distal acinar emphysema (paraseptal) – dilatation of the distal 3 rd respiratory bronchioles, alveolar ducts and sacs.may be seen more commonly in IV drug users.most common form is familial emphysema associated with a 1 antitrypsin abnormalities.more severe in lower zones of the lung bilaterally. ![]() (2) panacinar emphysema (panlobular) – destruction throughout the acinus, generally distal to the terminal bronchioles.can be seen in coal workers’ pneumoconioses.most common form of emphysema associated with symptomatic COPD.more severe in the upper zones of the lung bilaterally.(1) proximal acinar emphysema (centrilobular) – loss of elastic tissue in proximal part of acinus (respir.histologically see big holes which result from loss of elastic tissue by the elastases.elastases are found in macrophages (majority) or PMNs – cigarette smoke stimulates elastase release.Two forces driving elastic damage – ß anti-elastases or Ý elastases.loss of elastic tethers which aid in holding the small airways open during expiration.Pathology – obstruction of airways by the loss of elastic recoil.Definition – abnormal enlargement of airspaces distal to the terminal bronchiole, most frequently caused by tissue destruction but without significant fibrosis.an increase in resistance to airflow owing to partial or complete obstruction at any level, from the trachea and larger bronchi to the terminal and respiratory bronchioles. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |