Middle Mesiastinum Flashcards
how is the middle mediastinum divided?
Into a superior/ inferior
only the inferior is further divided in an anterior, middle, and posterior portions
what are the contents of the middle mediastinum?
- Heart
- Pericardium
- Root of Great Vessels
- Root of the lungs
- Phrenic nerves (and accompanying pericardiophrenic vessels)
where are the phrenic nerves located with respect to the lungs? where is the vagus nerve located with respect to the lungs?
phrenic = ANTERIOR to the root of the lungs vagus = POSTERIOR to the root of the lungs
what is the pericardium?
a sac enclosing the heart and the roof of the great vessels
what is the fibrous pericardium?
an outer layer of dense connective tissue that attaches to the superior surface of the diaphargm
what are the 3 most important things about the location of the fibrous pericardium?
- it is located superior to the most superior aspect of the heart, and eventually fuses with the adventitia of the great vessels
- it does NOT lie directly on the surface of the heart
- it is continuous below the heart and fuses with the central tendon of the diaphragm
how is the serous pericardium divided?
into parietal and visceral layers
where is the parietal pericardium located?
internal to the fibrous pericardium
where is the visceral pericardium located? what is an alternative name for it?
lines the heart (known as the epicardium)
what does the reflection of the serous pericardium onto the great vessels result in?
the transverse and oblique sinuses
what is a reflection?
change in direction ie change in direction of the serous pericardium leads to sinuses
where is the transverse sinus located with respect to the heart, great vessels, pulmonary vessels?
posterior to the heart
inferior to the great vessels
superior to the pulmonary vessels
where is the oblique sinus located?
posterior to the heart, BETWEEN the right and left pulmonary veins
what is the significance of the pericardium fusing with the central tendon of the diaphragm?
is causes the heart to move UP with EXHALATION and
DOWN with every INHALATION
what is the only layer of the pericardium that actually comes in contact with the surface of the heart?
visceral pericardium (epicardium)
what part of the heart takes up most of the anterior surface area when the heart is in the sternocostal position?
right ventricle
what part of the heart take up most of the posterior surface area of the heart when it is in the sternocostal position?
left ventricle
what separates the right atrium from the right ventricle?
coronary (atrioventricular) groove
what separates the right and left ventricles?
interventricular septum
where is the apex of the heart located/directed? where is located with respect to the base? to the left ventricle?
downward and to the left about 45 degrees from the median plane; it is more anteriorly located than the base.
IT IS THE MOST INFERIOR POINT ON THE HEART (usually marks the level of the left ventricle)
where is the base of the heart located? what does it include?
most SUPERIOR surface of the heart; contains the SVC,, aorta, pulmonary trunk
what is an area of ausculation?
exact position on the anterior aspect of the thoracic wall that you place a stethoscope on to listen to heart valves best sound transmission
where would a stethoscope be placed to hear the pulmonary valve?
in the 2nd left intercostal space, close to the sternum
where would a stethoscope be placed to hear the aortic valve
2nd right intercostal space close to the sternum
where would a stethoscope be placed to hear the mitral valve
left 5th intercostal space at the mid-clavicular line (over the apex of the heart)
where would a stethoscope be placed to hear the tricuspid valve?
just to the left of the lower part of the sternum near the 5th intercostal space
are the areas of auscultation located at the actual anatomical location of the valves?
no
where does the right atrium receive blood from?
the superior vena cava from above and the inferior vena cava from below at the sinus of the venae cavae (on the posterior aspect)
what is the sulcus terminalis cordis? where is it located?
a groove which separates the sinus venarum from the rest of the atrium; located at the posterior aspect of the right atrium (external anatomy)
what is the texture of the sinus venae cavae? where is it located?
smooth portion; located on the posterior aspect of the right atrium, at the entrance of the vena cava (SVC/IVC entrance)
what is the crista terminalis?
separates the sinus venae cava from the rest of the right atrium;
It is the internal representation of the sulcus terminalis
what are the pectinate muscles?
rough muscles ridges that covers the anterior side of the right atrium