Posterior Mediastinum Flashcards
Which vertebrae make up the posterior border of the posterior mediastinum?
T5-T12
What are the contents of the posterior mediastinum?
thoracic aorta, oesophagus, thoracic duct, azygous system of veins, sympathetic trunk
At what level does the thoracic aorta pass through the aortic hiatus in the diaphragm?
T12
What are the major branches of the thoracic aorta?
posterior intercostal arteries, bronchial arteries, oesophageal arteries, superior phrenic arteries
How many pairs of posterior intercostal arteries are there?
nine
How many pairs of bronchial arteries are there?
one or two, left bronchial arteries always arise directly from the thoracic aorta, while those on the right usually branch indirectly from a right posterior intercostal artery
Are the oesophageal arteries paired or unpaired?
unpaired
How many oesophageal arteries are there?
normally 2, but can be up to 5
Where do the superior phrenic arteries arise?
anterior aspect of the thoracic aorta at the aortic hiatu
What do the superior phrenic arteries supply?
superior aspect of diaphragm
Which is the posterior one, the aorta or the oesophagus?
oesophagus
What is the thoracic duct?
the largest lymphatic vessel in the body, allowing return of lymph from most of the body (all but the right superior quadrant) into the venous system
Where does the thoracic duct originate?
cisterna chyli in the abdomen
How does the thoracic duct enter the thorax?
aortic hiatus
While in the posterior mediastinum, the thoracic duct receives drainage from the ________
intercostal spaces
Describe the azygous system of veins
This venous network drains blood from the body walls and mediastinal viscera, and empties into the superior vena cava.
What are the three main veins of the azygous system?
azygous vein, hemiazygous vein, accessory hemiazygous vein
Which vein of the azygous system crosses the diaphragm through the left crus?
hemiazygous vein
which vein of the azygous system crosses the diaphragm through the aortic hiatus?
azygous vein
Which vein of the azygous system if formed by the union of the fourth to eighth intercostal veins?
accessory hemiazygous vein
At what level does the accessory hemiazygous vein drain into the azygous vein?
T7
How is the hemiazygous vein formed?
Formed by the union of the left lumbar vein and left subcostal vein.
At what level does the hemiazygous vein join the azygous vein?
T8
Which veins form the azygous vein?
right lumbar vein, right subcostal vein
Which vein does the azygous vein drain into?
superior vena cava
The sympathetic trunks are paired bundles of nerves that extend from the base of the skull to the ______
coccyx
Which nerves arise from the thoracic sympathetic trunks?
lower thoracic splanchnic nerves