internal nervous system of heart. very leaky cardiac muscle cells, depolarize to threshold very rapidly, slightly diff aps, very few sarcomeres. dont contract.
heart rate and coordination of myocardial contraction
intrinsic conduction system of heart
composed of pacemaker cells
sinoatrial node (SA node)
located in superior wall of RA, pacemaker normally sets heart rate
SA node inherent rate of depolarization
atrioventricular node (AV node)
located in floor of RA, near interatrial septum
AV node, inherent rate of depolarization
bundle of his (AV bundle)
passes from AV node into interventricular septum. conveys AP from atria into ventricles.
AV bundle inherent rate
2 bundles that pass down interventricular septum to apex. quickly transmits ap to apex.
bundle branches inherent rate and purkinje fibers
pass up ventricular wall, from apex forward.