pyright e The MeGraww-Hin Companies, Ine, Permission required for reproduction or display (a) ■ Phase3 Inactivation of ca2+ channel 0.15 Time(s) Outward K+ current dominates lK: Progressively increased 100 IK1: Regenerative K+ outward Current P (L) 0.15
◼ Phase 3 Inactivation of Ca2+ channel Outward K+ current dominates IK: Progressively increased IK1: Regenerative K+ Outward Current
pyright e The MeGraww-Hin Companies, Ine, Permission required for reproduction or display (a) ■ Phase4 Na+-Ca2+ exchange 0.15 Sarcolemmal Caz+ pump Time(s) SR Cazt pump 100 Na*-K pump P (L) 1.0 0.15 Time(s)
◼ Phase 4 Na+ -Ca2+ exchange Sarcolemmal Ca2+ pump SR Ca2+ pump Na+ -K+ pump
Chemical Electrostatic 2 0 Ca N K K+ K+EDK Fast Na K channel (io K channels K channel (ik, ikt channel a chann channe ls ik, ikl, io
a, the key ion channels (and an electrogenic transporter) in cardiac cells. K+ channels(green) mediate K+ efflux from the cell: Na+ channels (purple)and Ca2+ channels (yellow) Probable gene mediate Na+ and Ca2+ influx SCN5A respectively. The Na+/Ca2+ exchanger (red) is electrogenic, as it transports CACNAIC three na+ ions for each Ca2+ ion across the surface membrane b, lonic currents and genes underlying the cardiacaction potential. Top, depolarizing currents as functions of time and the ir corresponding genes; centre, a ventricular action potential,; bottom KCNJ2 repolarizing currents and their corresponding genes KCND KCNH2/KCNE From the following article: Cardiac channelopathies k KCNOT/KCNE1 Eduardo marban Nature 415, 213-218(10 January 2002) doi:10.1038/415213a k KCNK?
a, The key ion channels (and an electrogenic transporter) in cardiac cells. K+ channels (green) mediate K+ efflux from the cell; Na+ channels (purple) and Ca2+ channels (yellow) mediate Na+ and Ca2+ influx, respectively. The Na+/Ca2+ exchanger (red) is electrogenic, as it transports three Na+ ions for each Ca2+ ion across the surface membrane. b, Ionic currents and genes underlying the cardiac action potential. Top, depolarizing currents as functions of time, and their corresponding genes; centre, a ventricular action potential; bottom, repolarizing currents and their corresponding genes. From the following article: Cardiac channelopathies Eduardo Marbán Nature 415, 213-218(10 January 2002) doi:10.1038/415213a
Transmembrane SAN potentials recorded in different heart AVN regions BH PF TPF 300600ms
Transmembrane potentials recorded in different heart regions