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Cards In This Set
| Front | Back |
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The heart is composed of three layers name them.
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Endocardium-lines inside of heart and valves
myocardium-responsible for pumping action epicardium-exterior layer |
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The heart is encased in a thin, fibrous sac called the________, which is composed of two layers.
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Pericardium
two layers of the pericardium are the visceral pericardium (adheres to epicardium) and the parietal pericardium. The space between is called pericardial space. |
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The pericardial space is filled with 20ml of fluid. What is this fluids purpose?
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Lubricates the surface of the heart and reduces friction during systole.
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What is happening in the heart during diastole?
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All four chambers relax simultaneously, which allows the ventricles to fill in preparation for contraction. (also called relaxation phase)
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________ refers to the events in the heart during contraction of the two top chambers (atria) and two bottom chambers (ventricles).
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Systole
Unlike diastole, atrial and ventricular systole are not simultaneous events. Atrial systole occurs first, just at the end of diastole, followed by ventricular systole |
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The four valves in the heart permit blood to
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Flow in only one direction
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The ________ valves separate the atria from the ventricles
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Atrioventricular
The tricuspid valve, so named because it is composed of three cusps or leaflets, separates the right atrium from the right ventricle. The mitral or bicuspid (two cusps) valve lies between the left atrium and the left ventricle |
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During diastole, the tricuspid and mitral valves are?
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Open, allowing the blood in the atria to flow freely into the relaxed
ventricles. As ventricular systole begins, the ventricles contract and
blood flows upward into the cusps of the tricuspid and mitral valves,
causing them to close.
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The two _______ valves are composed of three leaflets, which are shaped like half-moons.
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Semilunar
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The valve between the right ventricle and the pulmonary artery is called the _______ valve
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Pulmonic
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The valve between the left ventricle and the aorta is called the ______ valve.
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Aortic
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The semilunar valves are closed during ______.
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Diastole
The semilunar valves are forced open during ventricular systole as blood is ejected from the right and left ventricles into the pulmonary artery and aorta. |
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Unlike other arteries, the coronary arteries are perfused during ________.
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Diastole.
With a normal heart rate of 60 to 80 bpm there is ample time during diastole for myocardial perfusion. However, as heart rate increases, diastolic time is shortened, which may not allow adequate time for myocardial perfusion. As a result, patients are at risk for myocardial ischemia, during tachycardia, especially patients with CAD. |
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The __ node, the primary pacemaker of the heart, is located at the junction of the superior vena cava and the right atrium
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SA
firing rate of 60 to 100 impulses per minute |
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The __ node, is located in the right atrial wall near the tricuspid valve
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AV
The AV node coordinates the incoming electrical impulses from the atria and after a slight delay (allowing the atria time to contract and complete ventricular filling) relays the impulse to the ventricles. |
