Mediastinum Flashcards
What is the mediastinum
Central compartment of the thoracic cavity between the pleural sacs
It contains all the thoracic viscera except for the lungs
Why is the mediastinum highly mobile
It contains hollow visceral structures united only by loose CT
Borders of the mediastinum
Superior - superior thoracic aperture
Inferior - diaphragm
Anterior - sternum and costal cartilages
Posterior - bodies of thoracic vertebrae
What divides the mediastinum into superior and inferior parts
Transverse thoracic plane:
Imaginary line that runs from the sternal angle to the T4/5 vertebra junction (intervertebral disk)
What is the inferior mediastinum further divided into and by what
Pericardium divides it into:
Anterior
Posterior
Middle
Blood vessels of the superior mediastinum
Arch of aorta - brachiocephalic, L common carotid and L subclavian arteries
Superior vena cava - L and R brachiocephalic, L superior intercostal, supreme intercostal and azygous veins
Nerves of the superior mediastinum
L and R vagus nerve
Phrenic nerve
Cardiac nerves
Sympathetic trunk
Non-neurovascular contents of the superior mediastinum
Thymus Trachea Thoracic duct Infrahyoid muscles Sternohyoid muscle Sternothyroid muscle
Contents of the anterior mediastinum
Sternopericardial ligaments Thymus (children only) Loose CT Fat Lymphatic vessels Lymph nodes Branches of the internal thoracic vessels
Organs in the middle mediastinum
Heart
Bifurcation of the trachea
Blood vessels in the middle mediastinum
Ascending aorta - L and R coronary arteries
Pulmonary trunk
Superior vena cava
Nerves in the middle mediastinum
Cardiac plexus
L and R phrenic nerves
Lymphatic structures in the middle mediastinum
Tracheobronchial lymph nodes
Blood vessels in the posterior mediastinum
Thoracic aorta (T4-12) - Posterior intercostal, bronchial, oesophageal and superior phrenic arteries
Azygous system - azygous, hemiazygous and accessory hemiazygous veins
Major organ in the posterior mediastinum
Oesophagus
