mediastinum and great vessels Flashcards
what are the 4 areas of the mediastinum
anterior (infront of heart), posterior (behind heart), superior (above sternal angle), middle (heart region)
what does thymus gland do/ how is it in adults and where is it
makes t lymphocytes. in superior mediastinum but may extend partly into anterior mediastinum
atrophied in adults?
what important bvs/nerves are in the superior mediastinum
- great vessels of heart: aorta , pulmonary trunk, superior vena cava
- phrenic and vagus nerves
how can you distinguish vagus from phrenic nerve
vagus loops under aortic arch and is more medial
phrenic is more anterior and goes to heart and diaphram
where do coronary arteries come from
ascending part of aorta
where do intercostal arteries come from
descending aorta
what connects the aorta and the pulmonary trunk
ligamentum arteriosum
where is the left recurrent laryngeal nerve?
behind ligamentum arteriosum between arch of aorta aand pulmonary trunk
where does trachea bifurcate to bronchi
t4-t5, sternal plane?
what is in the posterior mediastinum
- descending aorta
- azygous veins (hemiazygous veins, azygous)
- esophagus (vagal plexus)
- thoracic duct
- sympathetic trunks (splanchic nerves)
what forms the azygous vein
right ascending lumbar vein on posterior abdominal wall, right intercostal veins.
empties into superior vena cava from just above root of right lung
what forms the hemiazygous veins
inferior and superior formed by :
- left ascending lumbar vein on posterior abdominal wall
- left intercostal veins
- both cross midline at about t8 to drain into azyogus vein
which side of the body has hemiazygous veins and where do they join into azygous
left!! sup and inf, drain into azygous vein and drain from left intercosta; veins
join around t8
where does thoracic duct arise from? where is it in the thorax and what does it drain into
arise from cisterna chyli in abdomen
-ascends in thorax behind the esophagus, bw azygous and hemiazygous veins, on top of vertebral column
drains into left internal jugular vein and left subclavian vein!!
drains everything except the right arm/head and neck
what are the nerves of the thorax
intercostal nerves, sympathetic trunks, splanchic nerves, phrenic, vagus
which rami do intercostal nerves come from
t1-t12
what do white/gray rami communicantes do
white: spinal nerve to ganglia
gray: ganglia to spinal nerve
what are splanchic nerves- 3 types ,? where do they synapse and where do they pass into abdomen?
greater, lesser , least are the 3 types
-they are preganglionic sympathetic fibers, continuations of white rami communicantes that do not synapse in chain ganglia, pass into abdomen with descending aorta, synapse in ganglia on surface of abdominal aorta !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-pass into abdomen with descending aorta
synapse in ganglia on surface of abdominal aorta
where does phrenic nerve originate (rami?), what does it do? which mediastinum is it in? which vein is it behind? what is it anterior to?
c3,c4,c5 origin
- motor innervation of diaphram
- in superior and anterior mediastinum
- behind brachiocephalic vein
- anterior to : subclavian arteries, aortic arch, pulmonary arteries, roots of lungs, pericardium
what does the vagus nerve supply and which system? where does it enter posterior mediastinum? what are its its branches?
parasympathetic nerves to thorax and abdomen
- eenter from neck behind brachiocephalic veins, in front of arteries
- each side branches into recurrent (inferior) laryngeal nerves and esophageal plexus
where do right/ left recurrent laryngeal nerves loop?
right loops under right subclavian artery
left loops under arch of aorta behind ligamentum arteriosum
both ascend along side of trachea to larynx
what/where does azygous drain
drains into superior vena cava from behind just above the root of the right lung
origin of esophageal plexus
vagus
which spinal nerves do white rami communicantes exist and what do they do
t1-l2, they communicate from spinal nerve to ganglia
