Mediastinum Flashcards
what structures enclose the mediastinum (sup, inf, ant, post)
sup- superior throacic apeture
Inf- diaphram
Ant- sternum and costal cartilages of true ribs
post- T1-12 vert bodies
What is the transverse thoracic plane and what does it divide + level
Divides mediastinum to sup and inf parts.
Goes thru sternal angle and IVD T4/5/bifurcation of trachea
where is the thymus located (+ in children)
Located just post to mandibrium in adults (in child it will get into the inf mediastinum)
Blood supply and venous drainage of thymus
Blood- int thoracic artery + 1st and 2nd intercostal aa
Venous- int thoracic vein + brachiocephalic trunks
Lymph drainage of thymus
Drains into parasternal tracheobronchial lymph nodes
where does the thoracic duct drain into
Left venous angle (int jug and subclavian meet)
What drains into the right venous angle (and what doesi it drain)
R lymphatic duct
-lymph produced by r head, neck, upper limb and thorax
Superior vena cava- location in relation to trachea/aorta, what nerve runs over it and what major vein drains into its post
anteriolat to trachea, right of ascending aorta (attaches to r mediastinal pleura
- R phrenic runs over it
- Azygos vein drains into its post
If a thymus tumor develops what could it compress and what s the symptoms
Can compress L brachciocephalic vein and cause edema in left upper limb
What is the ascending aorta part of and located in
in pericardial sac and belongs to the middle mediastinum
where does the arch of the aorta start and end
begins at 2nd chondral jt arches up towards left and sup to root of right lung and ends at ivd T4/5
Branches of arch of aorta (starting from closest to heart) + what % of ppl have this pattern
60% have this pattern
- Brachiocephalic trunk (divides into right subclav + R comon corotid)
- Left comon corotid
- Left subclavian
What is the ligamentum arteriosum and what did it connect and what nerve passes under
rementent of ductus arteriosus- connection bw left pulmonary artery to aortic arch
-left recurent pharyngeal passes under
what are the two parts of the trachea
cervical
thoracic- superior thoracic apeture down to where R + L main bronchi bifurcate
What does the R main bronchus pass infront of
What does L main bronchus pass infront and behind to
R- ant to axygos v (shorter and wider)
L- Ant to esophagus, inf to arch of aorta
If you inhaled an object where would it likely get stuck
sucked into r main bronchus and lodge in one of the lobar branches
Thoracic part of esophagus is ant and post to what
ant- to VB t1-4
post to trachea
a trachea tumor or aortic anerysium can compress this structure
upper part of esophagus causing swallowing issues
What are the 3 divs of the inf mediastinum
Ant, middle and post mediastinum
Where is the ant mediastinum located and contents
Bw sternum and pericardial sac
- Sternopericardial ligs, fat, retrostenal lyph nodes, int thoracic vessels, inf thymus (in children)
Where is the medial mediastunum located and contents (4)
located bw the ant and post walls of the pericardial sac
pericardial sac with heart inside, ascending aorta, pulmonary trunk, intrapericardial portion of SVC and IVC
where is the post mediastinum located (what is ant + post) and contents (4)
located bw post pericardial sac and VB T5-12
thoracic aorta, thoracic duct, azygos vein, lower part of esophagus + nerve plexus
Where does the thoracic aorta travel and what are the branches (6)
downward on left side of T5-12 (then becomes abdominal aorta)
Branches- Esophageal, pericardial, mediastinal (off front), bronchial, paired intercostal, sup phrenic
where does the thoracic duct originate and travel to
originates at level of L1/2, ascends with aorta on post side bw azygos vein and drains into l venous angle
what is the lower part of the esophagus located bw
bw the pericardial sac ant and post t5-10 VB
Where is the azygos vein located and what makes it up and drains into it
On right side of vert bodies.
formed by union of R ascending lumbar v and r subcostal v
also collects post intercostal veins on R except 1st
What does the hemi azygos vein collect and drain into
union of left ascending lumbar w left subcostal + lower 3 left post intercostal v
then crosses and drains into azygos
what does the accessorzy hemi azygos drain
left 4 middle intercostal veins into azygos
Path of R phrenic n and inn
-descends ant to scalene and decendis on r braichicephalic and sup vena cava and r pericardial sac
Inn- supplies mediastinal and diaphragmic pleua, pericardial sac, r diaphram and cystic nerve plexus (gallbladder)
Inflammation of gall bladder will refer to what dermatomes
R c4,5 dermatomes
Right vagus nerve path and end targets
enters ant to subclavian artery, gives off branch to reccurent laryngeal nerve here that ascends back up to inn larynx.
Will continue to descend post to root of lung and divides into many branches to go to pulmonary n plexus, to cardiac n plexus and esophageal n plexus. At exit point of mediastinum most of the fibres of r vagys nerve turns to post vagal trunk which exits thru esophageal hiatus
Sympathetic trunk- Branches
T1-5- cardiopulmonary splanchnic
t5-9- Esophageal, greater splanchnic and cilia ganglia
T10-11- lesser splanchnic
t12- lesser splanchnic
path of left phrenic n and inn
left side of aortic arch and root of lung + pericardial sac and ends when entering diaphram
inn- Supplies mediastinal pleura, diaphramatic pleura, pericaldial sac, diaphram (L)
Left vagus n path and branches
enters bw l common carotid and subclavian. Passes over l aortic arch and gives off to l larengeal reccurent n (ascends to supply l vocal mm and l larynx). After it passes past to root of left lung it gives off branches to pulmonary and cardiac and esophageal nerve plexus. At exit point it will be called ant vagal trunk
what is coarctation of aorta
narrowing of arch of aorta before or after the insertion of ligamentum arteriosum
-causes low BP in lower limbs
What is double arch of aorta and what can it cause
Arch will split and two and wrap esophagus and trachea
-breathing/swallowing complaints
