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The Cardiac Cycle and Blood Pressure. Wednesday, March 20th. Cardiac Cycle. One complete heartbeat is a full cardiac cycle Composed of two phases Systole Diastole During (ventricular) systole the ventricles contract During (ventricular) diastole the ventricles relax. Cardiac Cycle.
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The Cardiac Cycle and Blood Pressure Wednesday, March 20th
Cardiac Cycle • One complete heartbeat is a full cardiac cycle • Composed of two phases • Systole • Diastole • During (ventricular)systole the ventricles contract • During (ventricular)diastole the ventricles relax
Cardiac Cycle Cardiac Cycle Animation
Heart Sounds Lubb-Dupp • Lubb - First heart sound. AV Valves close, semilunar (aortic and pulmonary) valves open. Beginning of systole. • Dupp - Second heart sound. Semilunar valves close. Beginning of diastole. Heart Sounds
Blood Pressure • Remember!!! • The arteries are very elastic! • We can take a pulse using an artery. • What happens to someone's pulse if they lose a lot of blood? • Why? • Determined using a sphygmomanometer and a stethoscope OR an electronic sphygmomanometer
Blood Pressure • Measurement of arterial pressure produced during the cardiac cycle • Measure systolic and diastolic pressure • Which will have the higher reading? Why? • Normal blood pressure is below 120/80 • 120 is the systolic pressure • Pressure caused by blood being pumped into the aorta during systole • Highest amount of pressure on the arteries • 80 is the diastolic pressure • Pressure caused by ventricular relaxation during diastole • Lowest amount of pressure on the arteries
Taking Blood Pressure As you watch the video, answer these questions: 1. How should you sit? 2. How should your arm be placed? 3. List 2 things you should not do while having your blood pressure taken. 4. Where should the cuff be placed? 5. How is the systolic (top) measurement determined? 6. How is the diastolic (bottom) measurement determined?
Blood Pressure Problems • Hypertension -- high blood pressure • Causes • too much blood • high salt intake causes high blood pressure • arteries are too narrow or too stiff • blood pressure tends to increase as we age • Hypotension -- extremely low blood pressure • Causes • some medications • going from sitting to standing, especially when dehydrated • Preeclampsia -- high blood pressure in late pregnancy • Causes unclear • Symptoms: sudden weight gain, swelling of the hands, feet and face • The only cure is to have the baby