Mediastinum PDF

Mediastinum 17  Mediastinum Definition: median part of thoracic cavity between 2 lungs Boundaries o Anterior: sternum o Posterior: vertebral column o Superior: thoracic inlet o Inferior: diaphragm o Lateral: both lung & pleurae...

Mediastinum 17  Mediastinum Definition: median part of thoracic cavity between 2 lungs Boundaries o Anterior: sternum o Posterior: vertebral column o Superior: thoracic inlet o Inferior: diaphragm o Lateral: both lung & pleurae DR.Hendawy “Mediastinum” 18 Subdivisions is divided by a plane at the sternal angle level into Superior mediastinum: o Muscles: sternothyroid & sternohyoid o Glands: Part of Thymus o Venous layer: Brachiocephalic veins & Superior vena cava & left superior ICV o Arterial layer: Aortic arch with Brachiocephalic & Left common carotid & Left subclavian o Nerves: phrenic nerves & vagi & Left recurrent laryngeal & sympathetic chain o Tubes: Trachea & Esophagus & Thoracic duct Inferior mediastinum which is subdivided into: A. Middle mediastinum: o Phrenic nerves o Pericardium o Heart o Superior & Inferior vena cava o Pulmonary trunk o Pulmonary veins o Ascending aorta DR.Hendawy “Mediastinum” 19 B.Anterior mediastinum 1. Part of Thymus 2. Lymph nodes 3. Superior sternopericardial ligaments 4. Inferior sternopericardial ligaments C. Posterior mediastinum o Esophagus o 2 vagi o Descending aorta o Thoracic duct o Azygous vein & Hemiazygi o Sympathetic chain o Splanchinic nerves DR.Hendawy “Mediastinum” 20  Changes at sternal angle level “angle of Louis”  Disc between T4 & T5  2nd costal cartilage  Pulmonary trunk bifurcate  Ascending aorta ends  Arch of aorta :begin & ends  Descending aorta begins  SVC pierce pericardium  Azygous vein end in SVC  Tracheal bifurcate  Thoracic duct pass behind esophagus from Right to left DR.Hendawy “Mediastinum” 21