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        | The heart is bordered laterally by the |  | Definition 
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        | The heart is bordered posteriorly by the |  | Definition 
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        | The heart is bordered anteriorly by the |  | Definition 
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        | The heart lies below the _____ rib. |  | Definition 
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        | Space between the parietal and visceral layers of the pericardium that contains a small amount of serous fluid that reduces friction between the pericardial membranes as the heart moves within them. |  | Definition 
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        | The  visceral portion of the pericardium on the surface of the heart. |  | Definition 
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        | Thick middle layer of the heart that consists mostly of cardiac muscle tissue that pumps blood out of the heart chambers. |  | Definition 
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        | The inner layer of the heart that consists of epithelium and connective tissues that contains many elastic and collagenous fibers. |  | Definition 
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        | Blood that is low in oxygen and high in carbon dioxide enters the right atrium through the |  | Definition 
 
        | venae cave and coronary sinus. |  | 
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        | Blood flows from the venae cave to the |  | Definition 
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        | Blood flows from the tricuspid valve to the |  | Definition 
 
        | chamber of the right ventricle |  | 
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        | When the right ventricular wall contracts, the tricuspid valve closes and blood moves through the |  | Definition 
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        | Blood flows from the pulmonary valve and into the |  | Definition 
 
        | pulmonary trunk and its branches. |  | 
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        | The heart consists of ____ chambers. |  | Definition 
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        | After the left ventricle contracts, the _____ closes and the ______ opens, to allow blood to flow from the _____into the_______. |  | Definition 
 
        | aortic valve; mitral valve; left atrium; left ventricle |  | 
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        | As the left atrium contracts, more blood flows into the |  | Definition 
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        | When the left ventricle contracts with the mitral valve open, the mitral valve closes and the aortic valve opens, so blood flows into the |  | Definition 
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        | Part of the heart that seals the heart valves when it’s closed |  | Definition 
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        | There are three cusps for each valve except for the _______, which has only two. |  | Definition 
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