Model Mathematics

Component: environment

Component: intracellular_ion_concentrations

Ca_b=Ca_TRPN_Max-TRPN ddtimeTRPN=J_TRPN Ca_i=10001.8433e-7iftime<110001.055time10003-0.03507time10002+0.0003992time1000-1.356e-6iftime10time<1510000.014time10003-0.002555time10002+0.0001494time1000-1.428e-6iftime15time<5510001.739e-5time10003-3.209e-6time10002-5.689e-6time1000+1.719e-6iftime55time<25010000.0001321time10004-0.0002197time10003+0.0001374time10002-3.895e-5time1000+4.441e-6iftime250time<49010001.2148e-7otherwise

Component: thinfilaments

Component: tropomyosin

K_2=alpha_r2z_pn_Relz_pn_Rel+K_zn_Rel1-n_RelK_zn_Relz_pn_Rel+K_zn_Rel K_1=alpha_r2z_pn_Rel-1n_RelK_zn_Relz_pn_Rel+K_zn_Rel2 z_max=alpha_0Ca_TRPN_50Ca_TRPN_Maxn_Hill-K_2alpha_r1+K_1+alpha_0Ca_TRPN_50Ca_TRPN_Maxn_Hill Ca_50=Ca_50ref1+beta_1lambda-1 Ca_TRPN_50=Ca_50Ca_TRPN_MaxCa_50+k_Ref_offk_on1-1+beta_0lambda-10.5gamma_trpn alpha_Tm=alpha_0Ca_bCa_TRPN_50n_Hill beta_Tm=alpha_r1+alpha_r2zn_Rel-1zn_Rel+K_zn_Rel ddtimez=alpha_Tm1-z-beta_Tmz

Component: troponin

k_off=k_Ref_off1-Tensiongamma_trpnT_refif1-Tensiongamma_trpnT_ref>0.1k_Ref_off0.1otherwise J_TRPN=Ca_TRPN_Max-TRPNk_off-Ca_iTRPNk_on

Component: Myofilaments

ExtensionRatio=1iftime>10001otherwise lambda_prev=ExtensionRatio dExtensionRatiodt=0 lambda=ExtensionRatioifExtensionRatio>0.8ExtensionRatio1.151.15ifExtensionRatio>1.150.8otherwise

Component: filament_overlap

overlap=1+beta_0lambda-1

Component: length_independent_tension

T_Base=T_refzz_max

Component: isometric_tension

T_0=T_Baseoverlap

Component: Cross_Bridges

Q=Q_1+Q_2+Q_3 Tension=T_0aQ+11-QifQ<0T_01+a+2Q1+Qotherwise ddtimeQ_1=A_1dExtensionRatiodt-alpha_1Q_1 ddtimeQ_2=A_2dExtensionRatiodt-alpha_2Q_2 ddtimeQ_3=A_3dExtensionRatiodt-alpha_3Q_3