Mediastinum Flashcards
What is the mediastinum?
The mediastinum is an area found in the midline of the thoracic cavity, that is surrounded by the left and right pleural sacs
What is the mediastinum divided up into?
Superior and inferior mediastinum
What is the inferior mediastinum further divided up into?
What is the inferior mediastinum further divided up into?
What divides the mediastinum into superior and inferior sections?
A transverse plane that extends from the sternal angle (manubriosternal junction), to the intervertebral disc between T4 and T5 vertebrae.
What are the borders of the superior mediastinum?
First rib (superior) - T4 (inferior)
What can be found in the superior mediastium?
Thymus
Trachea
Esophagus
Aortic arch
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery
Internal thoracic arteries
Superior vena cava
Left superior intercostal vein
Brachiocephalic veins
Phrenic nerves
Vagus nerves
Left recurrent laryngeal branch of the left vagus nerve
Thoracic duct
Lymph nodes and vessels,
What are the borders of the anterior inferior mediastinum?
T4 (superior) - T9 (inferior)
Sternum (anterior) - pericardium (posterior)
What can be found in the anterior inferior mediastinum?
Remnants of the thymus, lymph nodes
What are the borders of the middle inferior mediastinum?
T4 (superior) - T9 (inferior); anterior aspect of pericardium (anterior) - posterior aspect of pericardium
What can be found in the middle mediastinum?
Pericardial sac
Heart
Origins of great vessels: pulmonary trunk, ascending aorta, pulmonary veins, superior vena cava, inferior vena cava
Tracheal bifurcation and main bronchi
Cardiac plexus
Phrenic nerves
What are the borders of the posterior mediastinum?
Lateral: Mediastinal pleura (part of the parietal pleural membrane).
Anterior: Pericardium.
Posterior: T5-T12 vertebrae.
Roof: Imaginary line extending between the sternal angle (the angle formed by the junction of the sternal body and manubrium) and the T4 vertebrae.
Floor: Diaphragm.
T4 (superior) - T12 (inferior); posterior aspect of pericardium (anterior) - spine (posterior)
What are the borders of the posterior mediastinum?
Lateral: Mediastinal pleura (part of the parietal pleural membrane).
Anterior: Pericardium.
Posterior: T5-T12 vertebrae.
Roof: Imaginary line extending between the sternal angle (the angle formed by the junction of the sternal body and manubrium) and the T4 vertebrae.
Floor: Diaphragm.
T4 (superior) - T12 (inferior); posterior aspect of pericardium (anterior) - spine (posterior)
What can be found in the posterior mediastinum?
Descending thoracic aorta and its branches
Azygos and hemiazygos venous systems
Thoracic duct & cisterna chyli
Esophagus and esophageal plexus
Vagus nerves
Thoracic splanchnic nerves (greater, lesser, least)
Lymphatics
