BIOL 121 Lecture Notes - Lecture 15: Heart Valve, Aortic Valve, Atrioventricular Node
Document Summary
Body fluids are good conductors of electricity. Cardiac impulses pass through the heart pass to surrounding tissue and to the surface of the body. If electrodes are placed in the skin around the heart, electrical potentials generated by the heart can be recorded. Ecg is the sum of all electrical events in the heart both depolarizing and repolarizing. The extent and type of disturbances of rhythm or conduction. The extent and location of myocardial damage. The cardiac cycle shows all the mechanical and electrical events during a single contraction on the left side of the heart at rest. Includes : pressure changes in the aorta, left atrium and left ventricle, volume changes in left ventricle, valves opening and closing, ecg. Cardiac cycle consists of a period of: systole (ventricular contraction, diastole (ventricular relaxation) Each cycle is initialed by the sa node. The impulse spreads rapidly throughout the atria and is conducted into the av node and then into the ventricles.
