(Solved): Which one of the following is wrong about SA potential? At threshold V-gated Ca2+ channels open, cr ...

Which one of the following is wrong about SA potential? At threshold V-gated Ca2+ channels open, creating upstroke and contraction 5pontaneous depolarization is caused by $\mathrm{Na}+$ flowing through channel that opens when hyperpolarized (HCN channels) Membrane voltage begins at $?60\mathrm{mV}$ and gradually depolarizes to -40 threshold Repolarization is via opening of $\mathrm{V}$-gated $\mathrm{Na}+$ channels