Mediastinum

Mediastinum.

Areas of the chest cavity, containing the right and left lungs, surrounded by the pleural cavity, called pleuropulmonary fields, regiones pleuropulmonales. Parietal pleura fused with hilar fascia, fascia endothoracica. Its site on the costal pleura level is nadplevralnut membrane, membrana suprapleuralis, as part of the intrathoracic fascia on the diaphragmatic pleura level diafragmoplevralnoy called fascia, fascia phrenicopleuralis.

Remaining between the two pleural space bags, containing a whole range of bodies and a limited front chest, back - the spine, from the bottom - tendinous part of the diaphragm, and the top facing the upper aperture of the thorax, called the mediastinum, mediastinum.

The upper mediastinum, mediastinum superius, is limited to the front handle of the sternum, in the back - the spine (reaching Thv level), and on the sides - the upper portions mediastinal pleura, trachea to the level of division into the main bronchi. It contains a number of organs, major blood vessels and nerves. So, here lie the lower 2/3 of the trachea, the upper half of the thoracic part of the esophagus, of the thymus (in children) or its replacement tissue, aortic arch, both brachiocephalic vein and most of the superior vena cava, the upper half of the thoracic duct, lymph nodes, part of the vagus and phrenic nerves, sympathetic trunk.

The lower mediastinum, mediastinum inferius, begins below the horizontal plane drawn at the level of the tracheal bifurcation. Its front wall is a body of the sternum, back - the spine, side - mediastinal pleura below the level of divergence from the main bronchi trachea and lower - tendinous part of the diaphragm. It is divided into front, middle and posterior mediastinum.

Anterior mediastinum, mediastinum anterius, located between the sternum and the anterior surface of the pericardium. It has the form uzkoyo gap approaching in shape to an equilateral triangle, the base of which is directed downwards. In the anterior mediastinum lie single anterior mediastinum, okologrudinnoy predperikardialnye and lymph nodes, as well as branches of the internal thoracic arteries and veins.

Average mediastinum, mediastinum medium, occupies most of the lower mediastinum. It contains the heart , surrounded by the pericardium, pulmonary trunk, pulmonary veins, the bifurcation of the trachea to the main bronchus, the lower half of the phrenic nerve and lateral pericardial lymph nodes.

Posterior mediastinum, mediastinum posterius, limited pericardium front and rear surface of the bifurcation of the trachea and main bronchi, the back - the spine (ThV-ThXII) and on the sides - the vertebral part of the mediastinal pleura. It houses the lower half of the thoracic esophagus, thoracic aorta, inferior vena Vienna, unpaired and hemiazygos veins, the lower part of the thoracic duct, vagus nerves and lymph nodes (intercostal, posterior mediastinum, upper diaphragmatic, prespinal, lower tracheobronchial, and others.) the lower part of the thoracic sympathetic trunks.