Question

A student postulated that the sodium pump directly causes action potentials along neurons. Is this hypothesis reasonable?A) No; action potentials result in increased permeability of the plasma membrane to sodium.B) No; the myelin sheaths of neurons prevent movement of ions across the plasma membranes of the neurons.C) Yes; sodium is transported out of neurons during action potentials.D) Yes; action potentials are accompanied by the hydrolysis of ATP.

Answer 1

Answer:A) No; action potentials result in increased permeability of the plasma membrane to sodium.

Explanation

Action potential is generated when influx of sodium ions occurs through the voltage gated ion channels in the nodes of ranvier cells, into the axoplasm. Provided the stimulus is strong enough more Sodium gated channels open and Sodium ions move in.

As sodium pump only pump sodium ions out of the cells , and it is sodium inlfux that causes action potentia,l this does not cause action potential .

In addition ATPs hydrolysis which supply energy for the sodium pump does not lead to action potential.