楊州大学YANGZHOUUNIVERSITYQuizL. Which one is correct in describing the action potentiaof ventricularcellsA. onlyk+flow out in plateau phaseB. the main ions in plateau phase are kt, Ca2+C.afferentNa+causedrepolarizationD.only Na+flows out in whole repolarization phase ofventricularcellsE.Ca2+flows outthecells inplateauphase
1. Which one is correct in describing the action potential of ventricular cells. A. only k+ flow out in plateau phase B. the main ions in plateau phase are k+ , Ca2+ C. afferent Na+ caused repolarization D. only Na+ flows out in whole repolarization phase of ventricular cells E. Ca2+ flows out the cells in plateau phase
Transmembrane potential of autorhythmiccells and its ionic mechanismsContractilecellsAutorhythmiccellsPhase 4 stable potentialPhase 4 spontaneous depolarizationResting potentialMaximal repolarization potential
Transmembrane potential of autorhythmic cells and its ionic mechanisms Contractile cells Autorhythmic cells Phase 4 stable potential Phase 4 spontaneous depolarization Resting potential Maximal repolarization potential
Ill. Sinoatrial cells---Normal pacemaker cellcopyriphOTheMcotae-Hllcoonie:e.PeSinoatrial(SA)nodeAtrioven-Leftatriumtricular(AV) nodeAtrioven-tricular(AV)bundle-LeftventricleLeftandrightbundlebranchesPurkinje fibersApex
III. Sinoatrial cells -Normal pacemaker cell
Sinoatrial cells: Slow response autorhythmic cellsCopyrigt(a)(Λw)03senre1. Maximal repolarizationThreshold-50qeypotential: - 70 mV4-1000.30C0.15Time (s)(b)2. Threshold potential : - 40 mV10.02L1.0PNa(nPca2-m100e0.10.150.300Time (s)
Sinoatrial cells: Slow response autorhythmic cells 1. Maximal repolarization potential: - 70 mV 2. Threshold potential : - 40 mV
3. AP of SA node cells and its mechanism20A山0mV-0mvB12030LActivation0-60ThresholdI, Inactiratio80ICa-l150300J65mVTime(ms)Whenthresholdisreached,fastcalcium1100mschannelsopenandcalciumrushesinSpike potential of the sinoatrial node cell1Ca2+Ca2+NatNatPhase O: When threshold potential reached -→L-type Ca2+channels open (Ica-L) -→Ca2+ influx
Phase 0：When threshold potential reached →L-type Ca2+ channels open（ICa-L）→Ca2+ influx. Threshold 0 mV Ca2+ Ca2+ 3. AP of SA node cells and its mechanism