BIOL 1119 Lecture Notes - Lecture 5: Electrical Conduction System Of The Heart, Interatrial Septum, Atrioventricular Node
25 Jan 2017
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Karina da rosa: the heart, cardiac muscle i. ii. Cardiocytes: heart cells : short and branched cells, laid down in layers surrounding the chambers of the hear iii. Sarcoplasmic reticulum: t-tubules bring in calcium to the cardiocyte, helps activate muscle contraction iv. Intercalated discs: join cardiocytes end to end. Desmosomes i: enables cells to pull on each other without pulling each other apart during contraction, electrical junctions i. Gap junctions: allow ions to flow between cardiocytes allowing for coordinating contractions, essential for effective pumping, cardiac conduction system i. Properties: myogenic, heartbeat signal for contraction originates within the heart, cardiocytes, autorhythmic ii. Regular, spontaneous depolarization: coordinated by a cardiac conduction system, composed of an internal pacemaker and nervelike conduction pathways iii. Structures: sinoatrial (sa) node (natural pacemaker, modified cardiocytes in the right atrium b, signals from the sa node excite atrial cardiocytes. Spread throughout the atria and stimulate the contraction of the atria: atrioventricular (av) node, electrical gateway to ventricles i.
