Superior Mediastinum Flashcards
(46 cards)
What is the parallel of the RML in the left lung?
Lingula
- Not true lobe but region of L lung
How to ID abnormalities of the RML on XR?
- Right heart border will be obscured on frontal view
- Heart will be obscured on lateral view but posterior is clear
How to ID abnormalities of the RUL on XR?
- Opacity will be above the major (horizontal) fissure on frontal view
- Same on lateral view
How to ID abnormalities of the RLL on XR?
- Opacity in lower region w/ blunting of costophrenic angle on frontal view
- Opacity will be in retrocardiac region on lateral view
*Check heart border to see if also possible RML
How to ID abnormalities of LUL on XR?
- Left upper lung opacity on frontal view
- Clear heart borders & retrocardiac region on lateral
*Lingular would cause loss of left ventricle border on both views
How to ID lingular abnormalities?
- Lose left heart border on frontal view
- Heart is hyperdense on lateral view while retrocardiac area is clear
Transverse thoracic plane
- Divides superior & inferior mediastinum
- Aka sternal angle
What divides the mediastinum into superior & inferior parts?
Transverse thoracic plane or sternal angle
What level is the transverse thoracic plane/sternal angle at?
T4-T5
What is most superficial in the superior mediastinum?
Remnant of thymus
What does the superior mediastinum containt?
- Great vessels (arch of aorta, brachiocephalic trunk, left common carotid artery, left subclavian artery, SVC, R&L brachiocephalic veins, bifurcation of pulmonary trunk & roots of pulmonary arteries)
- Trachea
- Esophagus
- Remnant of thymus
- Phrenic, vagus, & LEFT recurrent laryngeal nerves
- Cardiac plexus
- Thoracic duct
Which thoracic level does the SVC form?
1st costal cartilage
Which level does the arch of the aorta form?
Sternal angle (T4-T5)
Ligamentum arteriosum
- Attaches inferior part of aortic arch to superior part of left pulmonary artery
- Remnant of ductus arteriosus
What ligament attaches the aortic arch to the left pulmonary artery?
Ligamentum arteriosum
Name the arteries in the superior mediastinum.
(Right to left)
- Brachiocephalic trunk –> right subclavian artery + right common carotid artery
- Left common carotid artery
- Left subclavian artery
Where do the internal thoracic arteries branch from?
R&L subclavian arteries
What first branches off of the subclavian arteries?
Internal thoracic arteries
What are the internal thoracic arteries also known as?
Mammarian arteries
Name the nerves in the superior mediastinum.
- R&L phrenic nerves (superficial)
- R&L vagus nerves (deep)
- Left recurrent laryngeal nerve
What nerve wraps around the aortic arch (behind the ligamentum arteriosum)?
Left recurrent laryngeal nerve
What nerve wraps around the right subclavian artery?
Right recurrent laryngeal nerve
What does the left recurrent laryngeal nerve wrap around?
Aortic arch
What does the right recurrent laryngeal nerve wrap around?
Right subclavian artery