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Cardiovascular

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Heart

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  • Topic Anchor: Heart 
    • Structure:
      • 4 chambers: right atrium, right ventricle, left atrium, left ventricle
        • Blood flows from atrium to ventricle
        • Left ventricle thicker/more muscular than right ventricle
          • Left ventricle must supply systemic circulation (high pressure)
          • Right ventricle supplies pulmonary circuit (low pressure)
      • 4 valves:
        • Atrioventricular valves: prevent backflow into atria
          • Tricuspid valve: between right atrium and ventricle
          • Mitral/bicuspid valve: between left atrium and ventricle
        • Semilunar valves: prevent backflow into ventricles
          • Pulmonary semilunar valve: between right ventricle and pulmonary vein
          • Aortic semilunar valve: between left ventricle and aorta
      • Heartbeat (Cardiac Cycle)
        • Diastole:
          • Ventricles relax
            • Lowest pressure of cardiac cycle
          • Atrioventricular (tricuspid and mitral) valves open
            • Blood flows from atria to ventricles (filling)
        • Systole:
          • Ventricles contract
            • Highest pressure of cardiac cycle
          • Semilunar (aortic and pulmonary) valves open
            • Blood pumped out of heart