superior/posterior mediastinum Flashcards
what defines the region of the superior mediastinum
above the sternal angle.
largest features of the superior mediastinum
great vessels and the trachea
primary branches from the aorta
1st right subclavian artery and right common carotid artery
2 left common carotid artery
3. left subclavian artery
regions of the superior mediastinum and contents of each region
retrosternal (veins): thymus, left branch of brachiocephalic v, superior part of the SVC
- intermediate (arteries): aortic arch, brachiocephalic trunk, left common carotid a, left subclavian a
- Pre-vertebral (visceral): trachea, esophagus, left recurrent laryngeal n.
cardiac plexus contains what type of autonomic fibers
pre ganglionic parasympathetic fibers
post ganglionic sympathetic fibers
phrenic nerves travel ____ to the root of the lung
anterior
vagus nerves travel ____ to the root of the lung
posterior
what happens at vertebral level t4/t5 with the trachea
bifurcates into primary bronchi
in a cross section of the superior mediastinum, what is more ant/posterior vagus nerves or phrenic nerves
phrenic nerves: anterior
vagus nerves: posterior
the aspect of the trachea facing the posterior esophagus is made of what? versus what makes up the arch?
the aspect of the trachea facing the esophagus is made of smooth muscle, to ease swallowing food when the esophagus expands. the arch of the trachea is made of cartilage.
what branch of nerves arise from the right and left vagus nerves
right and left recurrent laryngeal nerves
what does the right recurrent laryngeal nerve wrap around
the right subclavian a.
considered to be more in the root of the neck, vs the superior mediastinum
left recurrent laryngeal nerve loops around the
arch of the aorta and ligamentum arteriosum
what was the ligamentum arteriorsum called when it was a fetal shunt? what did this shunt connect
ductus arteriosus connects the aorta to the pulmonary trunk.
which branch of the recurrent laryngeal nerves has a shorter, more oblique course?
the right recurrent laryngeal nerve.
what is the phrenic nerve sandwiched between in the mediastinum
the mediastinal pleura and the fibrous pericardium
where is the posterior mediastinum
in the thoracic region, between the posterior wall of the pericardial sac and the posterior thoracic wall
the sternal angle is at what vertebral level
t4/t5
areas where the esophagus is narrowed?
the pharyngeal junction, aortic arch, tracheal bifurcation, esophageal hiatus of the diaphragm (t10)
how can an aortic aneurism make swallowing difficult
a bulge in the aortic arch can impinge on the esophagus. deviating or even constricting the esophagus making swallowing difficult.
how could an esophageal tumor cause troubled breathing
a bulge in the esophagus could push on the tracheal lumen causing labored breathing
why would a pancoast tumor cause horseness?
the right vagus nerve branches around the subclavian artery to form the right recurrent laryngeal nerve that supplies motor innervation to the larynx. this lies directly on the apex of the lung, a tumor would suppress this nerve causing horseness.
how does the left vagus nerve pass the aorta arch
? what does it contribute to
anteriorly, gives rise to the left recurrent laryngeal nerve posteriorly.
the left vagus nerve passes in what direction to the ligamentum arteriosum?
laterally
how would an aortic aneurism in the aortic arch, cause clinical presentation of horseness?
the bulge in the aorta would compress the left laryngeal nerve, which supplies motor function to the larynx (voice box)
where is the larynx found
the superior portion of the trachea, it is your voice-box that leads to your windpipe: trachea.