$\frac{d \mathrm{q\_gi\_W}}{d t}=\mathrm{v\_in\_W}-\mathrm{RT}\mathrm{k\_gi\_W}(\frac{\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}-\frac{\mathrm{q\_gi\_Na}}{\mathrm{q\_gi\_W}})-\mathrm{v\_out1\_W}\frac{d \mathrm{q\_pt\_W}}{d t}=\mathrm{k\_gl\_W}(\frac{\mathrm{E\_ac}(\mathrm{q\_ac\_W}-\mathrm{U\_ac\_W})}{(\mathrm{L\_ac\_W}-\mathrm{q\_ac\_W})^2}-\frac{\mathrm{E\_pt}(\mathrm{q\_pt\_W}-\mathrm{U\_pt\_W})}{(\mathrm{L\_pt\_W}-\mathrm{q\_pt\_W})^2})-\mathrm{RT}\mathrm{k\_pt\_W}(\frac{\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}-\frac{\mathrm{q\_pt\_Na}}{\mathrm{q\_pt\_W}})-\mathrm{v\_out2\_W}\frac{d \mathrm{q\_vc\_W}}{d t}=\mathrm{k\_cc\_W}(\frac{\mathrm{E\_ac}(\mathrm{q\_ac\_W}-\mathrm{U\_ac\_W})}{(\mathrm{L\_ac\_W}-\mathrm{q\_ac\_W})^2}-\frac{\mathrm{E\_vc}(\mathrm{q\_vc\_W}-\mathrm{U\_vc\_W})}{(\mathrm{L\_vc\_W}-\mathrm{q\_vc\_W})^2})+\mathrm{RT}\mathrm{k\_gi\_W}(\frac{\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}-\frac{\mathrm{q\_gi\_Na}}{\mathrm{q\_gi\_W}})+\mathrm{RT}\mathrm{k\_pt\_W}(\frac{\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}-\frac{\mathrm{q\_pt\_Na}}{\mathrm{q\_pt\_W}})-\mathrm{v\_lv\_W}\frac{d \mathrm{q\_ac\_W}}{d t}=\mathrm{v\_lv\_W}+\frac{\mathrm{k\_cc\_W}\mathrm{E\_vc}(\mathrm{q\_vc\_W}-\mathrm{U\_vc\_W})}{(\mathrm{L\_vc\_W}-\mathrm{q\_vc\_W})^2}-\frac{(\mathrm{k\_gl\_W}+\mathrm{k\_cc\_W})\mathrm{E\_ac}(\mathrm{q\_ac\_W}-\mathrm{U\_ac\_W})}{(\mathrm{L\_ac\_W}-\mathrm{q\_ac\_W})^2}+\frac{\mathrm{k\_gl\_W}\mathrm{E\_pt}(\mathrm{q\_pt\_W}-\mathrm{U\_pt\_W})}{(\mathrm{L\_pt\_W}-\mathrm{q\_pt\_W})^2}\frac{d \mathrm{q\_gi\_Na}}{d t}=\mathrm{v\_in\_Na}-\mathrm{kK\_gi\_Na}(\mathrm{q\_gi\_Na}-\mathrm{q\_giEpi\_Na})-\mathrm{v\_out1\_Na}\frac{d \mathrm{q\_giEpi\_Na}}{d t}=\mathrm{kK\_gi\_Na}(\mathrm{q\_gi\_Na}-\mathrm{q\_giEpi\_Na})-\frac{3\mathrm{k\_giEpi\_NKE}(\left(\frac{\mathrm{K\_Na}\mathrm{q\_giEpi\_Na}}{\mathrm{q\_giEpi\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2-\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_giEpi\_K}}{\mathrm{q\_giEpi\_W}}\right)^{2}e^{\frac{2F\mathrm{u\_giEpi\_e}}{\mathrm{RT}}})}{(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_giEpi\_Na}}{\mathrm{q\_giEpi\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_giEpi\_K}}{\mathrm{q\_giEpi\_W}}\right)^2)}\frac{d \mathrm{q\_pt\_Na}}{d t}=\mathrm{kK\_gl\_Na}(\mathrm{q\_vc\_Na}-\mathrm{q\_pt\_Na})-\mathrm{kK\_pt\_Na}(\mathrm{q\_pt\_Na}-\mathrm{q\_ptEpi\_Na})-\mathrm{v\_out2\_Na}\frac{d \mathrm{q\_ptEpi\_Na}}{d t}=\mathrm{kK\_pt\_Na}(\mathrm{q\_pt\_Na}-\mathrm{q\_ptEpi\_Na})-\frac{3\mathrm{k\_ptEpi\_NKE}(\left(\frac{\mathrm{K\_Na}\mathrm{q\_ptEpi\_Na}}{\mathrm{q\_ptEpi\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2-\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_ptEpi\_K}}{\mathrm{q\_ptEpi\_W}}\right)^{2}e^{\frac{2F\mathrm{u\_ptEpi\_e}}{\mathrm{RT}}})}{(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_ptEpi\_Na}}{\mathrm{q\_ptEpi\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_ptEpi\_K}}{\mathrm{q\_ptEpi\_W}}\right)^2)}\frac{d \mathrm{q\_vc\_Na}}{d t}=\frac{3\mathrm{k\_giEpi\_NKE}(\left(\frac{\mathrm{K\_Na}\mathrm{q\_giEpi\_Na}}{\mathrm{q\_giEpi\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2-\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_giEpi\_K}}{\mathrm{q\_giEpi\_W}}\right)^{2}e^{\frac{2F\mathrm{u\_giEpi\_e}}{\mathrm{RT}}})}{(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_giEpi\_Na}}{\mathrm{q\_giEpi\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_giEpi\_K}}{\mathrm{q\_giEpi\_W}}\right)^2)}+\frac{3\mathrm{k\_ptEpi\_NKE}(\left(\frac{\mathrm{K\_Na}\mathrm{q\_ptEpi\_Na}}{\mathrm{q\_ptEpi\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2-\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_ptEpi\_K}}{\mathrm{q\_ptEpi\_W}}\right)^{2}e^{\frac{2F\mathrm{u\_ptEpi\_e}}{\mathrm{RT}}})}{(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_ptEpi\_Na}}{\mathrm{q\_ptEpi\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_ptEpi\_K}}{\mathrm{q\_ptEpi\_W}}\right)^2)}-\mathrm{kK\_gl\_Na}(\mathrm{q\_vc\_Na}-\mathrm{q\_pt\_Na})\mathrm{u\_vc\_W}=\frac{\mathrm{E\_vc}(\mathrm{q\_vc\_W}-\mathrm{U\_vc\_W})}{(\mathrm{L\_vc\_W}-\mathrm{q\_vc\_W})^2}\mathrm{u\_ac\_W}=\frac{\mathrm{E\_ac}(\mathrm{q\_ac\_W}-\mathrm{U\_ac\_W})}{(\mathrm{L\_ac\_W}-\mathrm{q\_ac\_W})^2}\mathrm{u\_pt\_W}=\frac{\mathrm{E\_pt}(\mathrm{q\_pt\_W}-\mathrm{U\_pt\_W})}{(\mathrm{L\_pt\_W}-\mathrm{q\_pt\_W})^2}\mathrm{c\_vc\_Na}=\frac{\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\mathrm{c\_gi\_Na}=\frac{\mathrm{q\_gi\_Na}}{\mathrm{q\_gi\_W}}\mathrm{c\_pt\_Na}=\frac{\mathrm{q\_pt\_Na}}{\mathrm{q\_pt\_W}}\mathrm{c\_giEpi\_Na}=\frac{\mathrm{q\_giEpi\_Na}}{\mathrm{q\_giEpi\_W}}\mathrm{c\_ptEpi\_Na}=\frac{\mathrm{q\_ptEpi\_Na}}{\mathrm{q\_ptEpi\_W}}\mathrm{C\_vc\_Na}=1E3\mathrm{c\_vc\_Na}\mathrm{C\_gi\_Na}=1E3\mathrm{c\_gi\_Na}\mathrm{C\_pt\_Na}=1E3\mathrm{c\_pt\_Na}\mathrm{C\_giEpi\_Na}=1E3\mathrm{c\_giEpi\_Na}\mathrm{C\_ptEpi\_Na}=1E3\mathrm{c\_ptEpi\_Na}\mathrm{u\_gi\_osmotic}=\mathrm{RT}\mathrm{c\_gi\_Na}\mathrm{u\_vc\_osmotic}=\mathrm{RT}\mathrm{c\_vc\_Na}\mathrm{u\_pt\_osmotic}=\mathrm{RT}\mathrm{c\_pt\_Na}\mathrm{v\_gi\_W}=\mathrm{k\_gi\_W}(\mathrm{u\_vc\_osmotic}-\mathrm{u\_gi\_osmotic})\mathrm{v\_pt\_W}=\mathrm{k\_pt\_W}(\mathrm{u\_vc\_osmotic}-\mathrm{u\_pt\_osmotic})\mathrm{v\_gl\_W}=\mathrm{k\_gl\_W}(\mathrm{u\_ac\_W}-\mathrm{u\_pt\_W})\mathrm{v\_cc\_W}=\mathrm{k\_cc\_W}(\mathrm{u\_ac\_W}-\mathrm{u\_vc\_W})\mathrm{v\_gl\_Na}=\mathrm{kK\_gl\_Na}(\mathrm{q\_vc\_Na}-\mathrm{q\_pt\_Na})\mathrm{v\_gi\_Na}=\mathrm{kK\_gi\_Na}(\mathrm{q\_gi\_Na}-\mathrm{q\_giEpi\_Na})\mathrm{v\_pt\_Na}=\mathrm{kK\_pt\_Na}(\mathrm{q\_pt\_Na}-\mathrm{q\_ptEpi\_Na})\mathrm{v\_giEpi\_NKE}=\frac{3\mathrm{k\_giEpi\_NKE}(\left(\frac{\mathrm{K\_Na}\mathrm{q\_giEpi\_Na}}{\mathrm{q\_giEpi\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2-\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_giEpi\_K}}{\mathrm{q\_giEpi\_W}}\right)^{2}e^{\frac{2F\mathrm{u\_giEpi\_e}}{\mathrm{RT}}})}{(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_giEpi\_Na}}{\mathrm{q\_giEpi\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_giEpi\_K}}{\mathrm{q\_giEpi\_W}}\right)^2)}\mathrm{v\_ptEpi\_NKE}=\frac{3\mathrm{k\_ptEpi\_NKE}(\left(\frac{\mathrm{K\_Na}\mathrm{q\_ptEpi\_Na}}{\mathrm{q\_ptEpi\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2-\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3\left(\frac{\mathrm{K\_K}\mathrm{q\_ptEpi\_K}}{\mathrm{q\_ptEpi\_W}}\right)^{2}e^{\frac{2F\mathrm{u\_ptEpi\_e}}{\mathrm{RT}}})}{(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_ptEpi\_Na}}{\mathrm{q\_ptEpi\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_Na}\mathrm{q\_vc\_Na}}{\mathrm{q\_vc\_W}}\right)^3)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_vc\_K}}{\mathrm{q\_vc\_W}}\right)^2)(1+\left(\frac{\mathrm{K\_K}\mathrm{q\_ptEpi\_K}}{\mathrm{q\_ptEpi\_W}}\right)^2)}\mathrm{q\_tot\_W}=\mathrm{q\_ac\_W}+\mathrm{q\_vc\_W}+\mathrm{q\_gi\_W}+\mathrm{q\_pt\_W}+\mathrm{q\_giEpi\_W}+\mathrm{q\_ptEpi\_W}\mathrm{q\_tot\_Na}=\mathrm{q\_vc\_Na}+\mathrm{q\_gi\_Na}+\mathrm{q\_pt\_Na}+\mathrm{q\_giEpi\_Na}+\mathrm{q\_ptEpi\_Na}$