BIOC34H3 Lecture Notes - Lecture 1: Cardiac Output, Purkinje Fibers, Hypertrophy
Document Summary
Jan. 8, 2017: arteries carry blood away from the heart while veins carry blood to the heart. Conduction system of the heart: the heart uses pacemaker cells that have no resting membrane potential, action potential starts in the sinoatrial (sa) node, from here, electrical activity will spread throughout the heart, the heart muscles are. Not contractile but serve to spread the electrical activity throughout the heart: general pathway of conduction is as follows, sinoatrial (sa) node starts the ap and initiates the intermodal pathway that converges onto the atrioventricular (av) node. Current that converges anywhere else in heart will not be conducted. Conduction also slows at av node, allowing the atrium to fully contract. Purkinje fibre to the contractile muscles of the ventricle: the atriums contract before the ventricles, blood squeezed from bottom to the top. Jan. 8, 2017: k+ channels re-open, l-type channel close. Voltage-gated na+ channels open, allowing na+ to flow into the cell.