1. The Mediastinum Flashcards
What are the divisions of the mediastinum?
Superior, inferior (anterior, middle and posterior)
What are the contents of the superior mediastinum?
Thymus
Veins (brachiocephalic and SVC)
Phrenic (C3,4,5), vagus and recurrant laryngeal nerves
Arteries (aortic arch and great vessels)
Trachea
Oesophagus
Thoracic duct
Lymphatic trunks
What spinal level is the trachea and where is the carina?
What spinal level is the oesophagus?
C6 - T4, T4/5
C6 - T10
Where is the superior and inferior mediastinum division?
Transthoracic plane/manubriosternal joint (sternal angle) T4/5
What are A, B and C?
A: Phrenic nerve
B: Vagus nerve
C: Recurrant laryngeal nerve
What is the phrenic nerve sensory and motor to?
Sensory to pericardium
Motor to diaphragm
How do the L and R recurrant laryngeal loop back?
L under aortic arch
R under R. subclavian artery
What 3 structures does the vagus innervate in the mediastinum?
Oesophagus
Heart
Bronchi
What does the anterior mediastinum contain?
Thymus
What does the middle mediastinum contain?
Pericardium, heart
What does the posterior mediastinum contain?
Primary bronchi
Oesophagus (and oesophageal plexus)
Descending aorta
Thoracic duct
Axygos and hemi azygos veins
What are the pericardium layers?
Fibrous
Parietal
Visceral
What does the fibrous pericardium do?
Protective, anchors heart - attached to great vessles and diaphragm, prevents over dilation
Which pericardium layer is the epicardium associated with?
Visceral
What is pericardial effusion/tamponade?
Fluid buildup between parietal and visceral pericardium
What are A,B, and C?
A: fibrous pericardium
B: parietal pericardium
C: visceral pericardium
What are the 3 heart wall layers and what are they made of?
Out to in:
Epicardium: visceral pericardium
Myocardium: cardiac muscle, bundles
Endocardium: continuous with endothelium
What comprises the serous pericardium?
Parietal and visceral pericardium
What is A?
Azygos vein
What is the basic structure of the thoracic arterial supply?
Internal thoracic artery -> aterior intercostal arteries (run with corresponding vein and nerve as bundle)
Descending aorta -> posterior intercostal arteries (3-12)
AI and PI anastomose in each intercosta space
EXCEPT 1 and 2, which branch from costocervicl trunk of subclavian.
What is the order from inferior to superior of the intercostal neurovascular bundle?
VAN
What are A, B and C?
A: posterior intercostal artery
B: lateral cutaneous branch
C: anterior intercostal artery
What are the main compoents of the thoracic venous drainage system?
Anterior intercostal veins -> internal thoracic vein
Posterior intercostal veins -> azygos vein (R) and hemi azygos veins (L)
What are A and B?
A: azygos vein
B: hemiazygos vein
What are 6, 9 and 10?
- Internal thoracic artery
- Thyrocervical trunk
- Costocervical trunk
