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How the heart works. HEART PHYSIOLOGY. HEART SOUNDS. Blood turbulence from closing valves 2 sounds: lubb (closing of valves between atria and ventricles) Dupp (closing of valves after ventricles). ELECTROCARDIOGRAM (ECG or EKG). Recorded electrical currents of heart
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How the heart works. HEART PHYSIOLOGY
Blood turbulence from closing valves • 2 sounds: • lubb (closing of valves between atria and ventricles) • Dupp (closing of valves after ventricles)
Recorded electrical currents of heart • Determine healthy heart
Vol. of blood through any tissue for a given time period. • Factors: • Cardiac output: heart rate x stroke volume • Blood pressure • Blood volume • Resistance • Size of vessel diameter • Blood viscosity • Total blood vessel length
High blood pressure • Major cause of heart failure and stroke • Causes: • Overweight • Excessive alcohol • Lack of exercise • Diet: high salt, low minerals (K, Ca) • stress
pulse • Alternating expansion and recoil of an artery • Wrist pulse = radial artery • Neck pulse = carotid artery
Blood pressure • Generated by contraction of ventricles • Pressure exerted by blood on walls of a blood vessel • Highest in aorta; falls as distance from left ventricle increases • Bp, as a vital sign, measures pressure in aorta/large arteries
Blood pressure • 2 measurements: systolic (heart contraction) and diastolic (relaxation) pressure. EX. 120/80 • Affected by cardiac output and peripheral resistance