Increased _____ permeability of nodal cells hyperpolarizes the SA node.

Question

Quizplus · Accepted Answer

Increased potassium permeability of nodal cells leads to an efflux of positively charged potassium ions, which causes hyperpolarization of the cell membrane and a decrease in the rate of firing in the SA node. This is because hyperpolarization makes the cell less excitable and takes longer to reach the threshold potential for an action potential to occur. Therefore, choice C is the best answer.

Increased _____ Permeability of Nodal Cells Hyperpolarizes the SA Node