PHGY 210 Lecture Notes - Lecture 5: Atrioventricular Node, Intercalated Disc, Gap Junction

• School: McGill University
• Department: Physiology
• Course: PHGY 210
• Professor: John White

Document Summary

The activation start at sinoatrial node, this is the pace maker. This action spread through the atrium, down the bundle of his, down the bundle branch to the purkinje fibers. The fiber lines inner most surface area of the muscle. The action travel to endocardium and epicardium all at the same time. The purpose of the branching is to bring the action simultaneously to the endocardium at both ventricle. This allow both ventricle be activated at the same time. The action potential is what goes through the cells and cause action. The branching action allow the simultaneous contraction of all ventricle. Both contract at once and give a powerful contraction. The cell here is the working myocardium, cells are long. The action potential will be proprigate along the axis of the cell. Intercalated disk are the specialized structure joined the cells, this hold the 2 cells together. The space between cells is called interstitial space.