The Mediastinum Flashcards
what are the boundaries of the mediastinum
superior thoracic aperture
inferior thoracic aperture
sternum
thoracic vertebrae
what vertebral level is the transthoracic plane and what does this divide
the transthoracic plane is an imaginary line b/w vertebral bodies T4/T5 that divides the mediastinum into superior and inferior sections
what structures pass through the superior mediastinum
PVT Left BATTLE
Phrenic nerve
Vagus nerve
Thoracic ducts
left recurrent laryngeal nerve
Brachiocephalic veins
aortic arch and branches (L. CCA, L. subclavian, brachiocephalic trunk)
Trachea
Thymus
Lymph node
Esophagus
how is the inferior mediastinum further divided?
into anterior, middle and posterior sections
what are the contents of the anterior mediastinum? what are its boundaries?
inferior thymus, fat, lymph nodes
bounded by the parietal pleura, diaphragm and sternal angle
what are the main structures in the middle mediastinum
the heart and pericardium
what are the contents of the posterior mediastinum
the inferior esophagus, thoracic aorta, azygos and hemiazygos veins
what are the branches of the ascending aorta
right and left coronary arteries
what are the branches of the aortic arch
brachiocephalic trunk
left common carotid artery
left subclavian artery
what are the branches of the brachiocephalic trunk
the right common carotid artery
the right subclavian artery
what contributes to form a brachiocephalic vein?
the internal jugular vein and the subclavian vein
what joins to form the SVC
The left and right brachiocephalic veins
where does the SVC drain?
into the right atrium
what two veins form the IVC
the left and right common iliac veins
give a brief description of azygos venous system
they are a collateral circulation b/w the IVC and SVC, they drain blood from pericardium, the posterior thoracic wall and bronchi.
hemiazygos on the left, azygos on the right, hemi drains into azygos, azygos drains into SVC
where does the pulmonary trunk arise from?
the right ventricle
what are the branches of the pulmonary trunk
left and right pulmonary arteries, they carry deoxygenated blood to the lungs for CO2 exchange for O2
what do the pulmonary veins carry and where do they drain
they carry oxygenated blood from the lungs and drain into the left atrium
describe the course of the right recurrent laryngeal nerve
this arises from the r. vagus nerve, anterior to the r. subclavian artery, hooks around this artery and ascends b/w trachea and esophagus to supply the larynx
describe the course of the left recurrent laryngeal nerve
branch of the l. vagus nerve at inferior border of the aortic arch, passes inferiorly to the arch, ascends b/w trachea and esophagus to supply the larynx
what are the spinal roots of the phrenic nerve
C3, C4, C5
what is the position of the phrenic nerve relative to the vagus nerve
the phrenic nerve runs laterally to the vagus nerve
what are the two layers to the serous pericardium
parietal and visceral
what are the atrioventricular valves
tricuspid on the right, mitral or bicuspid on the left
what are the semilunar valves
aortic and pulmonary valves
what does the aortic valve separate
the Left ventricle and the ascending aortaw
what does the pulmonary valve separate
the right ventricle and the pulmonary trunk
what is the relationship between the sulcus terminalis and the crista terminalis
the sulcus terminalis is on the external surface of the RA
the crista terminalis is on the internal surface of the RA
What chamber are the pectinate muscles located in
the RA
what are the chordae tendineae extensions of
they are extensions of the atrioventricular valve
what is the attachment of the chordae tendineae
to the papillary muscles
what are the trabeculae carneae
they are irregular muscular ridges in the ventricles
what is the significance of the semilunar cusps of the aortic valve?
the right cusp gives rise to the right aortic sinus which branches into the Right coronary artery
the left cusp gives rise to the left coronary sinus which branches into the left coronary artery
the posterior cusp is the aortic sinus
what are the branches of the right coronary arteries
the posterior interventricular artery
the right marginal artery
sinoatrial nodal branch
what are the direct branches of the left coronary artery
the anterior interventricular artery (LAD)
the left circumflex artery
name the branch of the LAD
diagonal branches
name the branch of the left circumflex artery
left marginal
what coronary artery does the great cardiac vein run with
the left anterior descending artery
what coronary artery does the middle cardiac vein run with
the posterior interventricular artery
what coronary artery does the small cardiac vein run with
the right marginal artery
where do the cardiac veins drain
into the coronary sinus on the posterior heart surface
what is meant by diastole
blood flows from major veins into the atria, then blood flows PASSIVELY into the ventricles
what is meant by atrial systole
when the atria contract to completely fill the ventricles
what is meant by ventricular systole
ventricles contract to push blood out of the heart
