Thorax 5: Superior and Posterior Mediastinum Flashcards
What are the subdivisions of the mediastinum
superior and inferior
What is the inferior mediastinum divided further into
anterior, middle, and posterior
What nerves are found in the superior mediastinum
phrenic, vagus, branches from sympathetic chain
What can the superior mediastinum be further divided into
retrosternal
intermediate
prevertebral
What are the contents of the retrosternal mediastinum
great vessels and thymus
What are the contents of the intermediate mediastinum
aortic arch
great branches
ligamentum arteriosum
nerves (phrenic, vagus, sympathetic cardiac branches)
Where is the brachiocephalic artery found and what will it divide into
comes off aorta on the right side: gives rise to subclavian and right common carotid
Where does the vagus nerve course within the mediastinum
follow esophagus into the abdomen
branches to form left recurrent under arch of aorta (right recurrent under subclavian)
What is contained in the prevertebral aspect of the superior mediastinum
trachea esophagus left recurrent laryngeal lymph nodes thoracic duct
What structures are contained in the posterior mediastinum
thoracic aorta esophagus (autonomic nerves) thoracic duct primary bronchi and nodes azygos system
What structures compose Kuleza’s triangle
thoracic aorta, azygos vein, and esophagus
What is contained in Kuleza’s triangle
thoracic duct
What type of arches are seen in the mediastinum
venous arch on right (azygos system)
arterial arch on left: aorta
What structures are seen in the mediastinum form the right side
azygos vein, vagus
What structures are seen in the mediastinum from the left side
aorta
vagus/left recurrent
esophagus
What are the 3 places esophagus may become compressed
esophageal hiatus at diaphragm
where it crosses aorta
left main bronchus
What are the 3 regions of muscle in esophagus
proximal 1/3: skeletal
middle 1/3: skeletal+ smooth
distal 1/3: smooth
What is the arterial supply to neck esophagus
inferior thyroid
What is the arterial supply to thoracic esophagus
branches from aorta
What is the arterial supply to abdominal esophagus
celiac artery from left gastric artery
What is the venous drainage of the esophagus
azygos: upper portion
portal system: lower portion
Where might an adenocarcinoma (Barrett’s esophagus) within the abdominal esophagus spread
liver through the portal system venous system
What is the innervation of the esophagus
parasympathetic: vagus
Symp: T1-T4
What is Virchow’s node
sign of esophageal or gastric cancer
Describe the relationship of the thoracic aorta to the esophagus
at first is positioned to the left then twists behind the esophagus
What are the smaller branches off the thoracic aorta
bronchial pericardial posterior intercostal superior phrenic esophageal mediastinal
What is coarctation of the aorta
narrowing of the aorta within the aortic arch, not completely occluded but impedes flow
How will the body compensate for coarctation of the aorta
use collateral vessels: internal thoracic, anterior intercostals, posterior intercostals
What does the azygos system drain
body wall
Where does the azygos system return venous to
SVC
What is the valsalva maneuver
exhaling forcibly with the glottis closed: compresses abdominal contents and backs blood up into azygos system
What are the pros of the azygos system
ensures blood gets back to the heart
What are the cons of the azygos system
valveless, easily spreads cancer, leads to skull and brain metastasis
What is the cisterns chyli
large sac that collects lymph from lower body and intestines: termination of thoracic duct
Where will the thoracic duct drain
left jugulovenous angle
What will the sympathetic chain give off on the medial aspect
cardiac nerves: in neck
Splanchnic nerves: in thorax
How many branches are found in greater, lesser, and least splanchnic nerves
greater: 3
lesser: 2
Least 1
What patten do splanchnic nerves follow
GVAs preganglionic enter sympathethetic chain without synapsing and leave. synapse at ganglia near organ
Where are preganglionic GVA cell bodies of splanchnic nerves found
bodies in IML
