Lecture 5 - The Mediastinum Flashcards
What are the 4 main regions of the mediastinum?
Superior and Inferior (anterior, middle, posterior)
What is the base of the superior mediastinum but the top border of the inferior mediastinum?
the sternal angle
What is the superior and inferior border of the mediastinum?
superior: rib 1 / superior thoracic aperture
inferior: diaphragm
What is the superior boundary of the mediastinum?
the superior thoracic aperture
What is the inferior boundary of the superior mediastinum?
the sternal angle
What is the lateral boundary of the mediastinum?
mediastinal surfaces of L+R lungs
What is the anterior boundary of the mediastinum?
manubrium
What is the posterior boundary of the superior mediastinum?
T1-T4 vertebrae
What are the organs found in the superior mediastinum?
esophagus, trachea and thymus
What are the vessels found in the superior mediastinum?
aortic arch + 3 branches
brachiocephalic veins (L+R)
SVC
arch of azygos
pericardiacophrenic vessels
thoracic duct
What are the nerves found in the superior mediastinum?
vagus nerves (L+R), left recurrent laryngeal nerve, phrenic nerves (L+R), sympathetic chains, & cardiac and pulmonary plexes
What do vagus nerves carry?
parasympathetic innervation
to many visceral structures
How do vagus nerves enter the thoracic cavity?
via superior thoracic aperture
What do some branches of the vagus nerve contribute to?
the cardiac plexus and pulmonary plexes
What does each vagus nerve give off?
a recurrent laryngeal branch
Which recurrent laryngeal branch is in the superior mediastinum?
the left one
What do recurrent laryngeal branches do?
innervate numerous neck structures
Where does the left recurrent laryngeal nerve pass?
posterior to the ligamentum arteriosum
What branch does the left recurrent laryngeal nerve come off of?
the right vagus nerve
What branch does the right recurrent laryngeal nerve come off of?
the left vagus nerve
Where does the left recurrent laryngeal nerve pass?
around the aortic arch
Where does the right recurrent laryngeal nerve pass?
around the left subclavian artery in the neck
What is the superior boundary of the anterior mediastinum?
sternal angle
What is the inferior boundary of the anterior mediastinum?
diaphragm
What is the lateral boundary of the anterior mediastinum?
mediastinal surfaces of the L+R lungs
What is the anterior boundary of the anterior mediastinum?
body of sternum
What is the posterior boundary of the anterior mediastinum?
pericardial sac
What are the organs found in the anterior mediastinum?
thymus (+ lymph nodes, adipose, loose connective tissue)
What is the anterior mediastinum primarily occupied by?
the thymus gland
What is the function of the thymus gland?
differentiation of T cells