What Is the Mediastinum?
A general term for organs, structures, and connective tissue between the left and right mediastinal pleura. The mediastinum is sagittal, located at the left and right of the thorax, narrowing up and wide down, short front and long back. The anterior boundary of the mediastinum is the sternum, the posterior boundary is the thoracic spine, the sides are the mediastinal pleura, the upper boundary is the upper thorax, and the lower boundary is the condyle. Under normal circumstances, the mediastinal position is relatively fixed. When pneumothorax occurs on one side, the mediastinum shifts to the opposite side [1] .
- Chinese name
- Mediastinum
- Foreign name
- Mediastinal
- Distribution
- The upper bound is the upper thorax and the lower bound is
- A general term for organs, structures, and connective tissue between the left and right mediastinal pleura. The mediastinum is sagittal, located at the left and right of the thorax, narrowing up and wide down, short front and long back. The anterior boundary of the mediastinum is the sternum, the posterior boundary is the thoracic spine, the sides are the mediastinal pleura, the upper boundary is the upper thorax, and the lower boundary is the condyle. Under normal circumstances, the mediastinal position is relatively fixed. When pneumothorax occurs on one side, the mediastinum shifts to the opposite side [1] .
Mediastinal quartet
- In this method, the mediastinum is divided into an upper mediastinum and a lower mediastinum at the horizontal plane of the sternum angle. The lower mediastinum is divided into anterior, middle, and posterior mediastinum, which is bounded by the pericardium.
- The mediastinum above the mediastinal sternal angle. The upper bound is the upper thorax, the lower bound is the plane from the angle of the sternum to the lower edge of the fourth thoracic vertebra, the sternal stalk is anterior, and the 1-4th thoracic vertebra is at the rear. In the upper mediastinum, there are thymus, left and right head arm veins, superior vena cava, phrenic nerve, vagus nerve, recurrent laryngeal nerve, aortic arch and its three major branches and the trachea, esophagus, and thoracic duct behind it.
- Mediastinum below the sternal angle of the mediastinum. The upper boundary is the lower boundary of the upper mediastinum, the lower boundary is the diaphragm, and the left and right sides are the mediastinal pleura. The lower mediastinum is divided into three parts. The anterior mediastinum is located between the front of the pericardium and the sternum. The pericardium and the surrounding heart are the mediastinum. The posterior mediastinum is between the pericardium and the thoracic spine.
- The anterior mediastinum is located between the sternum and the pericardium, and is very narrow. It only contains thymus or thymus remnants, anterior mediastinal lymph nodes, mediastinal branches of the internal thoracic artery, loose connective tissue, and pericardial ligament of the sternum. Frequent areas.
- The mediastinum is located between the anterior and posterior mediastinums and houses the heart and large blood vessels entering and leaving the heart, such as the ascending aorta, the pulmonary artery trunk, the superior vena cava root, the pulmonary artery and its branches, the left and right pulmonary veins, the ends of the odd veins, and the pericardium and pericardium Arteries, phrenic nerves, and lymph nodes. The mediastinum is the site of multiple pericardial cysts.
- The posterior mediastinum is located between the pericardium and the spine and chest, and houses the trachea branch and the left and right main bronchus, esophagus, thoracic aorta and sacral vein, hemi-singular vein, thoracic duct, sympathetic trunk and lymph nodes. The connective tissue and its interstitial space in the mediastinum extend upward through the upper thorax, down through the aortic and esophageal hiatus, and extend to the connective tissue and interstitial space of the neck and abdomen, respectively, so the mediastinal emphysema can spread up to the neck, Spread down to the retroperitoneal space. The posterior mediastinum contains multiple sites of bronchial cysts, neuromas, aortic aneurysms, and diaphragmatic hernias.