Pleura visceral

Pleura Folded membrane surrounding the lungs. Space between the visceral... 

Pleural cavity (space between visceral and parietal pleura)... 

The second factor is motion. The lung in the upper trunk (thoracic cavity) is encased by a lining membrane known as the visceral pleura. In fact, this is a dual membrane one membrane covers the lung and a second membrane lines the chest wall (the parietal pleura, see Fig. 3.1). Characteristics of the pleura are discussed later, but we mention this important tissue here because the movements of the lung are facilitated by the juxtaposition of the visceral and parietal pleura and the thin layer of fluid between them. 

Normally, the space between the visceral and parietal pleura is only a potential space. More accurately, it is a surface covered with a thin film of fluid, to lubricate movement of the lung. Both pleura are relatively flexible and passive, and do not limit the inflation or deflation of the lungs during the breathing cycle. 

Pleural effusions, fluid occurring between the parietal pleura and the visceral pleura, which is often transient and quickly absorbed, may or may not be induced by exposure to asbestos they are therefore also not strictly a part of asbestosis but can be associated as a symptom. Other symptoms include pleurisy (inflammation of the pleura), pain, and breathlessness. 

The pleura are connective tissue membranes composed of matrix, mesotheli-al cells, and fibroblasts. There are two types of pleural responses benign responses, such as thickening of the matrix, formation of plaques (which may calcify) or effusions, and fluid accumulation in the interpleural spaces between the visceral and parietal pleurae and neoplastic disease, or the malignancy known as mesothelioma. 

Q4 The pleura are serous membranes one layer (the visceral pleura) firmly adheres to the surface of the lung and the other (the parietal pleura) adheres to the inner surface of the thoracic wall and diaphragm. The two pleural membranes lie very close together, separated only by a thin him of fluid. This lubricates the pleural surface, allowing the two layers to smoothly slide over each other as the thoracic wall moves. 

Q5 When air enters the pleural cavity, either from the outside when the chest wall is punctured or from the lung itself if alveoli rupture, the visceral and parietal pleura become separated. The consequence of the introduction of air between the pleura is that the lung does not adhere to the pleura and thoracic wall when thoracic volume increases. Instead, the elastic fibres of the lung tissue and the surface tension of the air-water interface in the alveoli cause lung tissue to recoil and eventually collapse. To reinflate a collapsed lung the hole in the chest wall must be closed, a small tube placed in the pleural cavity and suction applied to remove the air from the cavity. 

A 30-year-old man, a cocaine sniffer, who had used cocaine more than five times a month for 4 years, complained of shortness of breath and acute chest pain. He had episodic cough and bloody sputum. A chest X-ray showed an 80% pneumothorax on the left side. On thoracoscopy the entire lung visceral pleura seemed to be covered by fibrinous exudate. After yttrium aluminium garnet (YAG) laser pleurodesis surgery, which abrades the pleura, he made a full recovery within 4 days. 

SERTL, K.,TAKEMURA, T TSCHACHLER, E FERRANS, V.J., KALINER, M.A. SHEVACH, E.M. (1986) Dendritic cells with antigen-presenting capability reside in airway epithelium, lung parenchyma and visceral pleura. Journal of Experimental Medicine, 163,436-451. 

FIGURE 12.61 This neoplasm consists of fleshy nodules attached to the visceral and parietal pleura. 

Talc, sterile powder, is an antineoplastic agent, that induces an inflammatory reaction, which promotes adherence of the visceral and parietal pleura, obliterating the pleural space and preventing reaccumulation of pleural fluid. It decreases or prevents recurrence of malignant pleural effusions. 

The bronchial arteries supply the trachea, pulmonary airways (both intra- and extrapulmonary), regional lymph nodes, (visceral) pleura, esophagus, and vasa vasorum of aorta and pulmonary artery and vein. 

MWCNTs C57BL/6J mice 10, 20, 40 and 80 pg/animal 1,7,28 and 56 days Penetrations of alveolar macrophages, the alveolar wall, and visceral pleura are both frequent and sustained 130... 

The perivenous plexus accompanies the veins into the perilobular septa and even reaches the visceral pleura to supply the subpleural alveolar walls. Spencer and Leof (1964) have described twigs of the venous plexus reaching and ramifying in the subendothelial space. A few ganglia are present in the perivenous plexus near the hilus. 

Subserous fascia is a loose, fibroelastic connective tissue. The visceral pleura, pericardium, peritoneum, and other capsular coverings of the visceral organs are representative examples. The tissue is also subject to inflammatory and infectious processes such as pleuritis or peritonitis. Pericarditis can severely tamponade the function of the heart. 

Fig. 2.1.15. Microscopic image showing a pleural plaque (P) overlying diffuse asbestos-induced pleural fibrosis (f). The visceral and parietal pleurae have fused, and chest wall muscle is visible at the right side of the image...

Pleural plaques are the most common thoracic lesions found in persons exposed to asbestos (Hillerdal and Lindgren 1980). These lesions predominantly involve the parietal pleura and are not associated with adhesions between the visceral and parietal pleural layers, unless there has been a complicating pleurisy or a surgical exploration (Schwartz 1991). Pleural plaques are most commonly found on the posterior wall of the lower half of the pleural spaces, laterally on the costal pleura, over the vertebrae, on the mediastinum, on the central part of the diaphragm. 

Diffuse pleural thickening involves the visceral pleura or both the visceral and parietal pleura and the subpleur al peripheral lung tissue. The word diffuse refers to its extent by opposition to circumscribed pleural plaques, but the definitions are numerous. On plain films, McLoud et al. have defined diffuse... 

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