KN 252 Lecture Notes - Lecture 7: Intercalated Disc, Skeletal Muscle, Electrophysiology
Document Summary
Fibers are arranged in bundles, which covers 3 planes. This is necessary so that when it contracts it squeezes blood out. Two types of cells found in cardiac muscle: Pacemaker cells think, branched, non-striated, non- contractile; modified heart cell; serve as the electrical conduction system (kind of like a nerve cell) Intercalated discs connect all heart cells with one another. This allows for communication from one cell to another. The intercalated discs are gap junctions reinforced (prevents gap junctions form ripping apart) with desmosomes. The intercalated discs are formed between contractile and other contractile cells; between pacemaker and other pacemaker cells; between contractile and pacemaker cells. Excitation initiated by pacemaker cells (the ap generated by these cells spreads through the intercalated disc to a neighboring contractile cell) Excites contractile cells (the contractile cell then generates an ap that travels to t-tubules to interior contractile cell)