PSL301H1 Chapter 2: Lecture 2 - reading
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PSL301H1 Full Course Notes
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Whenever the pp depolarize to thereshold, the wotuthythmis cell fires an ap. 60 if channel open, permeable to k and na. If clase and ca opens influx of ca continues depolarization. Na influx > k efflux slowly depolarize the cell. When threshold is reach, another set of ca opens, causing steep depolarization. Heart rate is determined by the speed which pacemaker cells depolarize. The heart as a pump electrical signals coordinate contraction. Depolarization star t in sinoatrial node (sa node) Internodal pathway content sa node the atrioventricular node (av node ) Into ventricles purkinje fibres in the ventricle transmit signal doan the atrioventricular bundle (av bundle) [divided into bundle branches ] Electrical signal for contraction begins when sa node fires an ao and spread through gap junctions. Slow through the contractile cell of the atria. Electrical signal cannot go from atria to ventricle, so it only goes to the av node.
