HLSC 3P90 Lecture Notes - Lecture 17: Purkinje Fibers, Atrioventricular Node, Sinoatrial Node

• School: Brock University
• Department: Health Sciences
• Course: HLSC 3P90
• Professor: Deborah O' Leary

Document Summary

Specialized cells that initiate the heartbeat and electrically coordinate contraction of the chambers: sinoatrial node sa node, atrioventricular node av node, bundle of his, purkinje fibres. P wave: atrial depolarization/systole, followed by qrs, 0. 06-0. 11 s, sa node rhythm 60-100 bpm with <10% variation, sinus bradycardia (<60 bpm, sinus tachycardia (>100 bpm, sinus arrhythmia variation (>10% with breathing) Pr interval: length it takes for the impulse to travel from the sa node to purkinje fibers, beginning of p to qrs. Interval of time between atrial and ventricular depolarization: 0. 12-0. 2 s duration. Qrs: ventricular depolarization/systole and atrial repolarization/diastole, follows p wave, 0. 06-0. 1s duration, beginning of q to end of s wave. St segment: beginning of ventricular repolarization/diastole, j point at end of qrs complex and beginning of st segment, end of qrs to beginning of t wave. T wave: ventricular repolarization/diastole, follows qrs, slightly asymmetrical.