KINE 3012 Study Guide - Quiz Guide: Cell Membrane, Trachea, Resting Potential

• School: York University
• Department: Kinesiology & Health Science
• Course: KINE 3012
• Professor: Michael Connor

Document Summary

Electrical stimulation at any point in the heart musculature (myocardium) results in simultaneous contraction of individual muscle cells (myocardial fibres: allows heart to function as an effective pump, contraction (systole), relaxing (diastole) Automaticity: myocardium is able to electrically stimulate itself in the absence of neural input. Sympathetic & parasympathetic nerves modulate rate of depolarization & repolarization that is intrinsic to the heart. Sa node: group of specialized cells located in the right atrium that regulates the electrical cycle of the entire myocardium, natural pacemaker. Electrical signal: sa node initiates electrical signal that spreads across right & left atria leading to depolarization & contraction of atria, depolarization goes to av node at base of right atria and the conduction velocity slows. Ensures atria empty completely into ventricles before ventricles contract. Allow sufficient time for ventricles to fill w/ blood prior to contraction: electrical signal travels through bundle of his splitting into right & left bundle branches.