Mediastinum Flashcards
whats the mediastinum ?
media = middle
stinum = between 2 objects
mediastinum is the area between the 2 lungs
from anterio posterior view where does it extend from?
from the sternum to the 12 T vertebrae
from a superior inferior view where does it extend from?
thoracic inlet to the diaphragm
how is the mediastinum divided into superior and inferior?
an imaginary line between the sternal angle ( manubrio sternal joint ) to the lower body of T4
above the line is superior
below it is inferior
what divides the inferior mediastinum ?
its divided by the pericardium sac
divides it into : anterior , middle , posterior
whats the superior boundary of the superior mediastinum?
superiorly by the thoracic inlet
whats the inferior boundary of the superior mediastinum?
inferiorly by the imaginary line ( from sternal angle to disk between T4, T5)
whats the anterior boundary of the superior mediastinum?
manubrium sterni
whats the posterior boundary of the superior mediastinum?
upper 4 thoracic vertebrae ( T1-T4)
what do forms the sides of the superior mediastinum?
mediastinal pleura
what are the anterior muscles that are found in the superior mediastinum?
Sternohyoid
sternothyroid
what are the posterior muscles that are found in the superior mediastinum?
longus coli posteriorly
what are the contents of superior mediastinum from anterior to posterior?
Manubrium
Thymus gland ( found also in the anterior mediastinum ) its directly manubrium sterni
Right and left brachiocephalic vein (unit to form SVC ) + LEFT SUPERIOR INTERCOSTAL VEIN
Aortic arch and its branches ( Brachiocephalic artery , left common carotid artery and then left subclavian )
Trachea ( Formed of hyaline cartilage + divides at the upper border of 5th thoracic , or lower border or 4th thoracic حسب مصادرك )
Esophagus ( enters the diaphragm at T10 , eggs at 10 )
whats the relation between the branches of the aortic arch?
the aortic arc is bending backwards so the branches are parallel to each others like the brachiocephalic is the most anterior one then the left common carotid and its behind the brachiocephalic and then behind it is the left subclavian and its the most posterior one
what are the nerves on the RIGHT side of the superior mediastinum ?
Right vagus –> directly on the right side of the trachea
Right phrenic nerve –> اقصى اليمين runs on the right side of the right brachiocephalic vein and SVC
what are the nerves on the LEFT side of the superior mediastinum?
Left vagus : Left side of the subclavian then to the left side of aortic arch
Left phrenic nerve : Descends on the LEFT side of left common carotid and then left side of aortic arch
Left recurrent laryngeal nerve : branch from left vagus and curves below aortic arch to go back to the larynx
Cardiac branches : from the 2 vagus nerves
which duct runs in the superior mediastinum?
thoracic duct runs on the left side of esophagus ( also runs in the posterior mediastinum )
which lymph nodes are found in the superior mediastinum?
brachiocephalic
Paratracheal and superior tracheobronchial groups
whats the origin of ascending aorta?
aortic orifice at the level of LEFT 3rd intercostal space (SVC was right 3rd costal cartilage )
whats the termination of ascending aorta?
Right 2nd costal cartilage by becoming the arch of aorta? ( 2nd costal cartilage cuz thats the sternal angle and the beginning of the superior mediastinum and we know that aortic arch is in the superior mediastinum
what are the branches of ascending aorta?
right coronary artery ( from the anterior sinus )
left coronary artery ( from the left posterior sinus )
whats the beginning of the aortic arch?
it begins at the termination of the ascending aorta ( right 2nd costal cartilage , sternal angle, superior mediastinum )