Mediastinum Flashcards
What divides the mediastinum into superior and inferior mediastina?
The transverse thoracic plane, TPP
What are the compartments of the inferior mediastinum?
Anterior, middle and posterior mediastina
Where can the transverse thoracic plane of Ludwig be found?
Runs thought the level of the manubrio-sternal angle of Louis and T4 intervertebral disc
What are the ABC’s of the TTP?
Arches: Aortic arch on the left, Azygous on the right
Bifurcations: tracheal and pulmonary trunk Bifurcations
Change in direction: esophagus and thoracic duct
What other structures can be found at the TTP besides the ABCs?
Tracheobronchial lymph nodes
Cardiac and pulmonary plexuses
Ligamentum arteriosum
Where is the superior mediastinum located?
Between the TTP and superior thoracic aperture
Where is the Thymus gland located?
In the inferior part of the neck and anterior part of the superior mediastinum, especially in children whom it is relatively large and readily recognizable on a chest X-ray
When does the thymus undergo involution?
After puberty
What is the thymus gland for?
Training of T-lymphocytes as part of cell-mediated immunity (CMI)
Where does the thymus receive its vasculature?
Mainly from branches of the internal thoracic artery
Where does the thymus gland’s lymph nodes drain into?
Para sternal nodes
What carcinoma is commonly seen in the thymus gland and with what disease is it commonly seen?
Malignant thymoma
Myasthenia gravis
What is the relationship between thymoma and myasthenia Travis?
50% of cortical thymoma patients develop myesthenia graves
15% of myasthenia gravis patients develop thymoma
What is myasthenia gravis?
An autoimmune neuromuscular junction disease caused in 85% of cases by acetylcholine receptor (AChR) antibodies
What forms the brachiocephalic vein?
Internal jugular and subclavian veins
How is the superior vena cava (SVC) and at what level is it found?
The left brachiocephalic vein crosses the midline to join the right brachiocephalic being to form the SVC at the level of the first chondrosternal joint, postero-lateral to the right margin of the sternum
When does the SVC receive the azygous vein?
At the level of the second chondrosternal joint
Where does the SVC end?
At the right atrium at the level of the 3rd sternochondral joint
Where does the SVC collect blood from?
Upper half of the trunk, upper limbs and head/neck
What does compression of the SVC lead to?
Superior mediastinal/VC syndrome
Symptoms: blu head, neck and upper limbs with engorged superficial veins
What are the arteries of the superior mediastinum?
Upper part of the arch of the aorta (and branches), namely the Brachiocephalic trunk, left common carotid and left subclavian arteries
Where does the arch of the aorta start?
Posterioylteral to the second sternochondrial joint at the level of the TTP)
Where is the concavity of the arch of the aorta?
TTP
What are the 3 bregular branches of the arch of the aorta
Brachiocephalic trunk, left common carotid artery and left subclavian artery