Introduction Primary function of the cardiovascular system is to maintain perfusion The heart serves as a pump login to view 1 more bullet Cardiac Output Cardiac output (CO) = stroke volume (SV) x heart rate (HR) login to view 4 more bullets SV is determined by login to view 8 more bullets SV increases with anxiety, exercise, and pregnancy Pulse pressure ∝ SV login to view 1 more bullet Distribution of CO login to view 1 more bullet Myocyte Action Potentials Initiated in the sinoatrial (SA) node, the pacemaker of the heart Slowed by the atrioventricular (AV) node, which allows for ventricular filling Action potential causes influx of Ca2+ ions, which triggers the release of Ca2+ from the sarcoplasmic reticulum login to view 1 more bullet Relative conduction velocities login to view 1 more bullet Myocardial O2 Demand Increased with login to view 4 more bullets Maintenance of Mean Arterial Pressure Mean arterial pressure (MAP) is maintained by login to view 5 more bullets MAP = CO x total peripheral resistance (TPR) MAP = 2/3 diastolic pressure + 1/3 systolic pressure