Mediastinum Flashcards
What is the mediastinum bounded by and what it includes
Bounding: superior thoracic apeture (thoracic inlet), diaphragm, sternum, throacic verterbral bodies, pleural cavities
Includes: heart, great vessels, trachea, oesophagus
Superior mediastinum where
From manubriosternal joint and lower T4 level to superior thoracic aperture
Major vessels in superior mediastinum
Arteries=brachiocephalic trunk, subclavian artery, right common carotid, left common carotid left subclavian, aortic arch
Veins: right and left branchiocephalic veins, right and left internal jugular, right and left subclavian
Inferior mediastinum where
manubriosternal joint to diaphragm.
Inferior mediastinum composition
anterior (fat and thymus gland remnant), middle (fibrous pericardium and heart) and posterior compartments (descending thoracic aorta, oesophagus, thoracic duct, azygos vein). Sympathetic trunks run alongside vertebral bodies
Path and function of vagus nerve
path: behind left main bronchus->behind heart->in front of descending thoracic aorta->hiatus
function: supplies oesophagus and trachea
Sympathetic contribution oesophagus and trachea level
T6-10
oesophagus begins where
C6
cricoid cartilage in larynx where
C6
Is the carnia in the mediastinum
No
Constrictions of oesophagus
Criocid cartilage C6, aortic arch T4, left main bronchus T5, left atrium T6-10, oesophageal opening T10
How are oesophageal muscles controlled
By the vagus. Upper part: voluntary somatic, somatic motor neurone.
Lower part: smooth, involuntary autonomic parasympathetic
Azygos system and levels of drainage
Hemiazygos vein drains to azygos Y7/8
Accessory hemiazygos vein drains to azygos T6/7
What muscle separates subclavian artery+vein
Serratus anterior
Phrenic nerve path
through thoracic inlet->heart border->hemidiaphragm
