Question

An action potential is a sequence of rapidly occurring events on an excitable membrane that provides a means of communication within the body. During the motor neuron action potential different modes of transport are utilised to generate the electrical signal. Identify and explain two different modes of membrane transport that occur during the motor neuron action potential.

Answer 1

During a motor neuron action potential, passive transport of Na+ ions causes depolarization when sodium channels open, and active transport of K+ ions leads to repolarization when potassium channels open.

Step-by-step explanation:

During the motor neuron action potential, two primary modes of membrane transport are utilized to generate the electrical signal. The first mode is passive transport of sodium ions (Na+) through sodium channels. When a neuron is stimulated, these channels open, allowing Na+ ions to flow into the cell. This influx of positive ions causes the membrane potential to change rapidly from negative to positive, a phase known as depolarization.

The second mode of transport is the active transport of potassium ions (K+) through potassium channels. Shortly after depolarization, potassium channels open, and K+ ions flow out of the cell. This movement helps to restore the negative charge inside the neuron, a process called repolarization. Both modes of transport are essential for the propagation of the nerve impulse along the neuron's axon.