HPER-P - Health, Physical Education And Recreation HPER-P 374 Lecture Notes - Lecture 2: Cardiac Muscle Cell, Electrocardiography, Qrs Complex

• School: IUPUI
• Department: HPER-P - Health, Physical Education And Recreation
• Course: HPER-P - Health, Physical Education And Recreation HPER-P 374
• Professor: Dr.Mc Kenzie

Document Summary

Depolarization the spread of the electrical stimulus along the heart muscle which normally leads to contraction. Repolarization the recovery of the stimulated muscle to its resting state; this prepares the muscle cell to be ready for the next depolarization. P wave represents atrial depolarization (begins at the sa node upper back wall of the right atrium) Atrial repolarization takes place during qrs (not visible) In the resting state, the environment inside a cardiac muscle cell is negatively charged relative to the outside of the cell. Also in the resting state, the environment immediately outside a cardiac muscle cell membrane is positively charged relative to the environment inside the cell. As the wave of positive charges move toward a surface electrode (which is also positive) an upward deflection is observed on the ekg oscilloscope or paper. If the positive wave of depolarization moves away from a surface electrode a negative deflection is observed.