AP Flashcards
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| 7435025046 | Cardiac cycle | Alternating systole and diastole leads to different periods | 0 | |
| 7435025047 | Ventricular filling | Blood passively flows into ventricles from atria through open AV valves (70%) ; heart is at rest | 1 | |
| 7435025048 | Atrial depolarization -------> | Atrial systole Moves remaining blood (30%) into ventricles | 2 | |
| 7435025049 | Ventricular depolarization -----> | Ventricular systole | 3 | |
| 7435025050 | Period of isovolumetric contraction | Ventricles contract, push blood against AV valves->AV valves close; pressure rises without change in volume | 4 | |
| 7435025051 | Period of ejection | Increased pressure in ventricles pushes semilunar valves open and blood forced into elastic arteries (pulmonary and aorta) | 5 | |
| 7435025052 | ventricular repolarization-----> | Ventricles relax Semilunar valves close when pressure in ventricles drops below pressure in aorta | 6 | |
| 7435025053 | Dicrotic notch | Increase in aortic pressure as blood pushes back against closed semilunar valve | 7 | |
| 7435025054 | Period of isovolumetric relaxation | Ventricles relax with both sets of valves closed; pressure drops but volume stays the same | 8 | |
| 7435025055 | Isovolumetric relaxation continues til | Until pressure in ventricles drops below pressure in atria-> AV valves open and filling begins again | 9 | |
| 7435025056 | 1st heart sound | "Lub" -closure of AV valves | 10 | |
| 7435025057 | 2nd heart sound | "Dup"-closure of semilunar valves | 11 | |
| 7435025058 | Murmur | Gurgling sound due to backwash of blood through valves or stenosis(narrowing) of valves | 12 | |
| 7435025059 | Cardiac output | Volume of blood ejected from each ventricle per minute | 13 | |
| 7435025060 | At rest, cardiac output is usually | 5 L/ min | 14 | |
| 7435025061 | CO = | HR x SV | 15 | |
| 7435025062 | Heart rate (HR) | Number of beats per minute | 16 | |
| 7435025063 | Heart rate varies with | Presence of sympathetic and parasympathetic inner action and presence of adrenal hormones (epinephrine/norepinephrine) | 17 | |
| 7435025064 | Stroke volume(SV) | Amount of blood ejected per beat | 18 | |
| 7435025065 | SV = | EDV-ESV | 19 | |
| 7435025066 | EDV | End diastolic volume(preload)- amount of blood in the ventricle at the end of filling/diastole ; normally 120-130 ml | 20 | |
| 7435025067 | ESV | End systolic volume-amount of blood in the ventricle at the end of contraction; normally 50 ml | 21 | |
| 7435025068 | Cardiac cycle | All events associated with blood flow through the heart during one complete heart beat | 22 | |
| 7435025069 | Cardiac output | Volume of blood ejected from each ventricle per minute | 23 | |
| 7435025070 | CO = | HR x SV | 24 | |
| 7435025071 | Main controller of stroke volume | Preload | 25 | |
| 7435025072 | Frank-starting law of the heart | Heart contraction adjusts to match venous inflow (stroke volume is sensitive to preload) | 26 | |
| 7435025073 | Greater venous return---->greater stretch---> | Stronger contraction | 27 | |
| 7435025074 | Decreased return--->less stretch---> | Weaker contraction | 28 | |
| 7435025075 | Afterload | Pressure of blood in arteries; must be overcome for blood to be ejected from ventricle | 29 | |
| 7435025076 | Higher afterload = | Smaller SV | 30 | |
| 7435025077 | Ventricular contractility | Measure of the ventricles ability to produce contraction force (independent of muscle stretch and EDV) | 31 |