Thorax 4: Mediastinum and Heart Flashcards
What are the different subdivisions of the mediastinum
Superior and inferior mediastinum
What divides the superior and inferior mediastinum
angle of louis: line from sternal angle to T4
The inferior mediastinum is divided further into what and how
based on coverings of the heart
anterior
middle
and poster
What are the boundaries of the superior mediastinum
thoracic inlet
sternum
vertebral bodies
What are the boundaries of the inferior mediastinum
diaphragm
sternum, pleural cavities, thoracic vertebral bodies
What type of space is the pericardial sac
potential space
What are the layers of the pericardial sac
fibrous outer layer serous pericardium (visceral and parietal)
Where will pericardiocentesis be performed
between parietal and visceral layer of the serous pericardium
What is the arterial and venous support of the pericardium
internal thoracic artery and aorta
Venous: brachiocephalic vein and azygos system
What is the innervation of pericardium
phrenic nerve
What vessels are associated with phrenic nerve
pericardiophrenic vessels
What are the two pericardial sinuses
Oblique and Transverse sinus
Where is the transverse sinus
space posterior to the ascending aorta and pulmonary trunk
What is important to note about the attachment of the pericardium on the heart
also covers the trunks of the great vessels
What is the apex of the heart
inferior, conical end. Tip of left ventricle
What is the innervation to the serous pericardium
Visceral: vagus
Parietal: phrenic
What is the anatomical base of the heart
posterior aspect composed of left atrium
What is the diaphragmatic surface of the heart
right and left ventricles that rest on diaphragm
What is the sternocostal surface of the heart
most anterior aspect composed of right ventricle
What is the right pulmonary surface of the heart
right atrium
What is the most anterior chamber of the heart
right ventricle
What is the most posterior chamber of the heart
left atrium
What composes the right side of the heart
right atrium
What composes the left side of the heart
left ventricle
Where is the coronary sulcus located
encircles the heart between atria and ventricles
Where is the inter ventricular sulcus found
between ventricles
What are the characteristic features of the right atrium
sinus venarum
pectinate muscles
fossa ovalis
What is the sinus venarum
smooth walls of right atrium
What is the fossa ovalis
remnant of foramen ovale
Where is the fossa ovalis located
right atrium on intertatrial septum
What are septomarginal trabeculae
extensions of cardiac muscle from inter ventricular septum to papillary muscles
What is the function of septomarginal trabeculae
carry parts of conduction system of the heart
What is the inflow tract of right ventricle
muscular
What is the outflow tract of right ventricle
trunks arterioses is smooth
What is the function of papillary muscles and chordae tendinae
papillary muscle connect to valves through chord tendinae which will pull the valves shut when contracted
What are the different parts of the inter ventricular septum
membranous and muscular portion
What portion of the inter ventricular septum do most presenting ISD occur
membranous portion
What are the characteristic features of the right ventricle
inflow outflow tracts papillary muscles moderator band tricuspid valve IV septum
What type of blood will enter the right atrium
deoxygenated
What are the associated veins that enter right atrium
IVC, SVC
coronary sinus
anterior coronary arteries
venus minimum
What type of blood will be found in the left atrium
oxygenated
What veins are associated with left atrium
pulmonary veins
What is the muscle of the left atrium like
smooth except for auricle
What are characteristics of left ventricle
inflow through mitral valve, smooth wall towards outflow to aorta, trabecualtions on bottom
List the sequence of signals through the conduction system of the heart
SA node
AV node
Bundle of his (right and left branches through IV septum to each ventricle) which communicates with purkinje fibers
Where is SA node located
where crista terminales and SVC meet
Where is the AV node
junction of atria and ventricles
Where is the bundle of His located
IV septum
Where are purkinje fibers located
walls of ventricles (endocardium)
How are valves of the heart anchored
through a DCT skeleton
Where will the heart valves be ausculatated
aortic: right 2nd intercostal space parasternally
Pulmonary: left 2nd intercostal space parasternally
Tricuspid: left 5th intercostal space parasternally
Mitral: left 5th intercostal space midclavicular
What are the main branches of the right coronary artery
marginal artery
posterior descending artery
SA nodal
What are the main branches of the left coronary artery
circumflex
left anteriordescending artery
left marginal
What determines dominance of the heart
what every coronary artery side the posterior descending artery comes off
Which coronary artery is longer
right
What are common variants of cardiac arteries
SA nodal can come off left
Posterior inerventricular can come off left circumflex coronary artery
What is the arterial support to the conducting system of the heart
SA node: right coronary artery
AV node: small vessel as right coronary becomes posterior interventricular
Right and Left bundle: LAD
What is the most common site of occlusion
LAD
What is the second most common site of occlusion
right marginal
What is the third most common site of occlusion
circumflex
What is CABG and what is used
coronary artery bypass grafting usually uses greater saphenous vein from leg
What is more common, right or left sided dominance of heart
right (75%)
What artery runs with LAD
great cardiac vein
What artery runs with right marginal
small cardiac vein
What artery runs with PDA
middle cardiac vein
What vein of the heart will drain directly into the right atrium
anterior cardiac veins
What levels are the sympathetic innervation to the heart
T1-T4 (5)
Where are the preganglionic GVE cell bodies that go to the heart found
IML of T1-T4
Where are the postganglionic GVE cell bodies that go to the heart found
cervical sympathetic chain
Where are the cell bodies that sense pain in the heart located
DRG of T1-T4
What type of neurons are contained within the sympathetic cardiac nerve
postganglionic GVE
GVA
Where is referred pain from the heart located to
left chest and down left arm (T1-T4 dermatomes), up neck too
What causes referred pain
convergence at DRG of GVA and GSA, and pain referred to GSA territory
Where is pericardiocentesis performed
under the xiphoid process and slightly to the left
What layers are traversed in pericardiocentesis
skin, superficial fascia, fibrous pericardium, parietal layer of serous pericardium
