Question

Transmission of impulses along a neuron in the vertebrate nervous system ordinarily occurs in only one direction because, following passage of an action potential, the neuron is temporarily in a refractory period or hyperpolarized. This is caused by which of the following?A. the movement of potassium ions out of the axonB. the movement of potassium ions into the axonC. the movement of sodium ions out of the axonD. the movement of sodium ions into the axon

Answer 1

Answer:

The movement of potassium ions out of the axon.

Explanation:

The membrane potential or cell potential is the difference in the electric potential outside and inside of the cell. The cell potential is important for the transmission of nerve impulse.

The resting  potential of the cells is -70mV. The movement of sodium ions causes the cell depolarization and makes the membrane potential more positive. The cells sometimes attain the more negative membrane potential stage known as hyperpolarization. This state mainly occur by the efflux or the movement of the potassium ions out of the axon.

Thus, the correct answer is option (A).