Sup/Post Mediastinum Flashcards
Where is the Superior Mediastinum?
Superior to a “line” from the eternal angle (anteriorly) to the T4/T5 intervertebral disc (posteriorly)
Contents of the Superior Mediastinum
Thymus,
Branchiocephalic veins, Superior Vena Cava, Arch of Aorta (and branches),
Phrenic, vagus, left recurrent laryngeal nerves, and cardiac plexus
Trachea, Esophagus, and Thoracic Duct
What is the Thymus?
A 2 lobed lymphoid organ help together by dense irregular connective tissue
Where is the thymus?
Between the sternum and base of heart
Size of the thymus?
~40 grams max around 10-12 yrs, then a trophies as you age, ~6grams around 65 yrs
Function of the Thymus?
It is the maturation sure of the T-lymphocytes
The superior vena cava branches off into the:
Right Brachiocephalic vein and left brachiocephalic vein
Each brachiocephalic vein branches off into:
A subclavian vein and an internal jugular vein
The superior vena cava descends into the:
Upper part of the right atrium
The superior vena cava is located in the:
Upper part is in the superior mediastinum and the lower part I in the middle mediastinum
What is the function of the Superior Vena Cava?
To return deoxy blood to the heart from all structures superior to the diaphragm
The superior vena cava returns blood from all the structures above the diaphragm except:
The heart and the lungs
The Superior Vena Cava receives one tributary , which is:
The Azygos vein (posteriorly) from the thoracic wall
What are the parts of the aorta?
Ascending aorta, arch of the aorta, descending aorta
The descending aorta divides into the:
Thoracic aorta and abdominal aorta (divided at the diaphragm)
The ascending aorta begins at the:
Aortic orifice of the left ventricle
Where does the ascending aorta terminate?
About 2” above the left ventricle (where it meets the arch)
Where does the ascending aorta lie?
Within the pericardial sac (middle mediastinum)
What are the branches of the ascending aorta?
Right coronary artery and left coronary artery
Where does the arch of aorta terminate?
To the left of the t4 vertebral body (where it meets the descending thoracic aorta) in the posterior mediastinum
What is the ligamentum arteriosum?
A fibrous band that connects the arch of the aorta to the left pulmonary artery
What is the ligamentum arteriosum a remnant of?
The fetal Ductus Arteriosis