January 4, 2016 - Anatomy of the Heart Flashcards
Divisions of the Thorax
Yellow = Superior mediastinum
Red = Middle mediastinum
Blue = Posterior mediastinum
Green = Anterior mediastinum
Mediastinum is just the space that contains the heart and the lungs.
We divide these areas in order to compartmentalize the organs
Pericardial Cavity
The potential space formed between the two layers of serous pericardium around the heart.
Normally contains small amounts of serous fluid that acts to reduce surface tension and lubricate the heart.
Cardiac Tamponade
Is a type of pericardial effusion in which fluid, pus, blood, clots, or gas accumulates in the pericardium (the sac in which the heart is enclosed), resulting in slow or rapid compression of the heart.
The heart has difficulty expanding and contracting and therefore cannot efficiently pump blood. Death often occurs because of the heart failing to pump blood rather than the fluid buildup itself.
Layers of the Heart Wall
The fibrous pericardium is on the outside, followed by the parietal serous pericardium, followed by the visceral serous pericardium, followed by the myocardium (thick layer), and finally the thin endocardium on the onside which holds the blood.
Heart Wall Thickness
The left ventricle is usually 15-30mm thick
The right ventricle is usually 5-10mm thick
Coronary Sulcus
A groove on the outer surface of the heart marking the division between the atria and the ventricles.
Interventricular Sulcus
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One of two grooves that seperates the ventricles of the heart
Papillary Muscles
Are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves via the chordae tendineae (parachute cords) and contract to prevent inversion or prolapse of these valves on systole (pumping).
There are a total of 5 papillar muscles in the heart; three in the right ventricle and two in the left.
Atrioventricular Valves
The right side is weaker with 3 cusps
Left side is stronger with 2 cusps
Chordae Tendinae
Similar to parachute cords
Attach the valve cusps to the papillar muscles
Semilunar Valves
Little “parachutes” that fill up with blood from the backflow.
On the pulmonary side, this just closes up the valve and prevents backflow.
On the aortic side, it not only closes, but passes through the coronary ostium and into coronary circulation.
Coronary Ostium
The opening of the coronary arteries at the root of the aorta just above the semilunar valves.
When blood flows out through the aorta, the backflow closes the semilunar valves and the blood enters the coronary circulation.
This is passive circulation
Heart Murmur
the sound produced when blood flows across one of the heart valves that is loud enough to be heard with a stethescope.
Aortic Stenosis
The narrowing of the exit of the left ventricle of the heart.
Often results in a heart murmur.
Coronary Circulation
Different people have different patterns.
The most common is right coronary artery dominance (67%).
Dominance refers to whichever artery supplies the posterior interventricular branch of the heart.
Hilum
The hila, or lung roots, are relatively complicated structures that consist mainly of the major bronchi and the pulmonary arteries and veins.
Found in the medial aspect of each lung.
The airway can be ideitified by the cartilagenous rings.
Conduction System of Heart
Myocardial Infarct
When a coronary artery becomes blocked, often due to a thrombus or a placque that has broken off and become lodged.
Causes the death of cardiac tissue.
Great Cardiac Vein
Opens into the left extremity of the coronary sinus.
It receives tributaries from the left atrium and from both ventricles.
