The mediastinum may be subdivided into a cranial portion cranial to the heart, a middle portion at the level of and containing the heart, and a caudal portion caudal to the heart. It acts as a pathway by which structures can pass from the abdominal wall to the external genitalia. This lower part is subdivided into three regions, all relative to the pericardium the anterior mediastinum being in front of the pericardium, the middle mediastinum contains the pericardium and its contents, and the posterior mediastinum being behind the pericardium. Middle mediastinum and the heart questions and study guide. Bounded in front by the sternum, behind by the pericardium, at the sides by the pleurae. The most common cause of a middle mediastinal mass is lymphadenopathy due to metastases or primary tumor. Subclavian artery carotid artery arteries and veins heart failure spinal cord heart wall fig middle illustration. Lizhenhua inferior mediastinum middle mediastinum location between anterior mediastinum and posterior mediastinum contents heart and pericardium. Mediastinum anatomy, boundaries, content, and division. Most patients are asymptomatic, but symptoms may arise from compression of the trachea or esophagus. The inferior part is further subdivided by the pericardium, which encloses the pericardial cavity enclosing the heart. The pericardium and heart make up the middle mediastinum the anterior mediastinum is located between the. It contains the heart, esophagus, trachea, thymus, and aorta. Generally, mediastinum is further divided into three main parts.
Thymoma is a common anterior mediastinal mass, alt hough thymomas have occasionally been found in. It is bounded by the undersurface of the sternum ventrally and the anterior. Clinical features diverse mass lesions can occur in middle and posterior mediastinum. The mediastinum is a large anatomic compartment in the thoracic cavity, bounded laterally by the pleurae, anteriorly by the sternum, posteriorly by the vertebrae, superiorly by the thoracic inlet, and inferiorly by the diaphragm. Mediastinum is divided into superior and inferior mediastinum by a plane which passes through manubriosternal joint and lower border of fourth thoracic vertebra. The mediastinum is the space in the middle of the chest between the two pleurae.
The most common mediastinal masses are neurogenic tumors 20% of mediastinal tumors, usually found in the posterior mediastinum, followed by thymoma 1520% located in the anterior mediastinum. Phrenic, deep cardiac plexus bifurcation of trachea with two principal bronchi tracheobronchial lymph nodes 15 16. Every compartment of the mediastinum contains many vital organs, vascular and neural. In addition to tracing the vessels of the heart, this video will give you an in depth look at some of its internal features. The inguinal canal boundaries contents teachmeanatomy. The middle mediastinum is the broadest part of the interpleural space. Anatomy thorax middle mediastinum anatomy, boundaries and content. Inferior mediastinum again divided into 3 parts anterior, middle and posterior by pericardium. Posterior mediastinum the posterior mediastinum is an irregular triangular space running parallel with the vertebral column. The mediastinum is the region between the pleural sacs. Chest radiology pathology mediastinal mass middle mediastinum. It extends from the thoracic inlet cephalad to the superior surface of the diaphragm caudad. The inferior mediastinum from this level to the diaphragm.
The borders of the mediastinum include the thoracic inlet superiorly, the diaphragm inferiorly, the spine posteriorly, the sternum anteriorly, and the pleural spaces laterally. Disorders of the mediastinum harrisons principles of. The anterior mediastinum extends from the sternum anteriorly to the pericardium and brachiocephalic vessels posteriorly. The mediastinum is the median partition between the two pleural cavities. A horizontal plane going through the sternal angle and the intervertebral disc between vertebrae tiv and tv splits the mediastinum into superior and inferior parts. From wikibooks, open books for an open world its compartments, and the mediastinal lymph nodes thomas w. Other causes include hiatial hernia, aortic aneurysm, thyroid mass, duplication cyst, and bronchogenic cyst. It contains the heart enclosed in the pericardium, the ascending aorta, the lower half of the superior vena cava with the azygos vein opening into it, the bifurcation of the trachea and the two bronchi, the pulmonary. The mediastinum may also be divided into dorsal and ventral portions by a dorsal plane through the tracheal bifurcation.
The middle mediastinum is an artificial space of the mediastinum divided from the remainder of the extrapleural intrathoracic cavity by arbitrary lines. Mediastinum anatomy, location, cavity, organs, function. You may not embed one of our images on your web page without a link back to our site. A mediastinal tumor is a tumor in the mediastinum, the cavity that separates the lungs from the rest of the chest. Diagnostic radiologychest imagingmediastinal masses. Quizlet flashcards, activities and games help you improve your grades. The mediastinum is an area found in the midline of the thoracic cavity, that is surrounded by the left and right pleural sacs. Pdf thymoma of the middle mediastinum researchgate.
Since this is the plane that separates superior mediastinum from inferior mediastinum heart is in middle, inferior mediastinum and trachea is in superior mediastinum. The majority of these lesions present as an asymptomatic mass on chest xray. Because thyroid goiters account for most mediastinal masses of thyroid origin, the demographics of thyroid mediastinal masses are similar to those of thyroid goiter, with a tendency to occur predominately in middleaged women. The main contents of middle mediastinum are pericardium and its contents example, the heart and roots of its great vessels. The inguinal canal is a short passage that extends inferiorly and medially, through the inferior part of the abdominal wall. From wikibooks, open books for an open world boundaries of the anterior, middle, posterior and superior mediastinum. It is superior and parallel to the inguinal ligament.
It is divided into the superior and inferior mediastinum, of which the latter is larger the inferior mediastinum is further divided into the anterior, middle and posterior mediastinum. Svc, termination of azygos, pulmonary veins nerves. It extends from the sternum to the spine, and contains all the viscera in the thorax except the lungs. The main contents of middle mediastinum are pericardium and its contents example.
It is separated into three compartments table 2891. The anterior boundary of the posterior mediastinum is the posterior pericardial wall. Extends from the sternum anteriorly to the vertebral column posteriorly, and from the thoracic inlet above to the diaphragm below. In the dissection of cadavers, the posterior mediastinum is exposed by removing the pericardial sac and the heart.
The posterior mediastinum or paravertebral compartment is a potential space along the paravertebral sulci. The book features more than 650 images, and downloadable copies of these are included on a cdrom, packaged with the print book. Pathology of the mediastinum will be of interest to practising surgical pathologists, thoracic surgeons, oncologists and radiologists. It contains the heart enclosed in the pericardium, the ascending aorta, the lower half of the superior vena cava with the azygos vein opening into it, the bifurcation of the trachea and the two bronchi, the pulmonary artery dividing into its two branches, the right and left pulmonary veins, the phrenic nerves. If you would like a large, unwatermarked image for your web page or. It forms the largest component of the inferior mediastinum. It is further subdivided into four arbitrary portions by the pericardium, namely, superior, anterior, middle, and posterior compartments. It is conceptually considered a portion of the inferior mediastinum, and separated from the middle mediastinal compartment and the remainder of the extrapleural intrathoracic cavity by arbitrary lines. The posterior boundary is the anterior surfaces of the bodies of thoracic vertebrae t5t12. Inferior mediastinum extends downwards, terminating at the diaphragm. The middle mediastinum is the pericardium and its cavity. In this article, we shall look at the anatomy of the middle mediastinum its borders, contents and clinical correlations. Middle mediastinum anatomy, boundaries and content. It is further subdivided into the anterior mediastinum, middle mediastinum and posterior mediastinum.
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