Mediastinum Flashcards
(49 cards)
mediastinum extends from _
posterior aspect of sternum to anterior aspect of thoracic vertebral column
superior border of mediastinum
superior thoracic aperture
inferior border of mediastinum
diaphragm
lateral boundaries of mediastinum
mediastinal portion of parietal pleura (lining of inner wall of thoracic cavity)
inferior mediastinum includes _
anterior, middle, and posterior
superior thoracic aperture is formed by _
innermost surface of thoracic rib I, anterior surface of body of thoracic vertebrae I, sternovascular joints, and jugular notch
lower border of SUPERIOR mediastinum
linear plane originating from sternal angle (between 4th and 5th thoracic vertebrae)
anterior border of superior mediastinum
manubrium
posterior border of superior mediastinum
body of T1 vertebrae to disc between T4-T5
superior mediastinum contains _
thymus, great vessels, brachiocephalic veins, superior SVC, pulmonary trunk and roots of pulmonary arteries, arch of aorta, brachiocephalic trunk, left common carotid artery, left subclavian artery, vagus and phrenic nerves, cardiac plexus, trachea, esophagus, thoracic duct
thymus
most anterior element within superior mediastinum (immediately behind manubrium)
thymus blood supply
branches of internal thoracic and internal intercostal artery
L/R brachiocephalic veins
lie immediately behind thymus –> merge together posterior to lower border of 1st costal cartilage to form SVC
L/R brachiocephalic veins are formed by _
junction of internal jugular vein and subclavian vein (venous angles)
venous angles
entry points for elements of lymphatic system (lymphatic on R and thoracic on L)
arch of aorta
slightly medial to the SVC, the aorta arches superiorly to the left over the right pulmonary artery then posteriorly behind the left pulmonary artery to continue on as the descending or thoracic aorta
posterior to aortic arch
bifurcation of trachea
branches of aortic arch
brachiocephalic trunk, left common carotid artery, left subclavian artery
right vagus nerve
enters superior mediastinum posterior, laterally to brachiocephalic artery
left vagus nerve
enters superior mediastinum between left subclavian artery and left common carotid, passing in front of aortic arch
vagus nerves (R+L)
will contribute to fibers to pulmonary, cardiac, and esophageal plexuses –> continue course in posterior mediastinum –> will form anterior and posterior vagal trunks
phrenic nerves (3,4,5 keeps diaphragm alive!) enter at
superior mediastinum b/tw subclavian artery and origin of brachiocephalic veins
right phrenic nerve
courses inferiorly lateral to the brachiocephalic vein and SVC –> passes anterior to the root of the lung and continues inferiorly towards the diaphragm along the lateral side of the pericardial sac
left phrenic nerve
courses inferiorly between the left subclavian artery and the left common carotid artery, crossing anteriorly over the aortic arch –> passes over the root of the lung and continues inferiorly towards the diaphragm along the lateral side of the pericardial sac
