Question

In response to a stimulus such as pain, a neuron sends a signal to the brain using __________.

a. contraction and relaxation


b. electrical signals and chemical neurotransmitters


c. respiration and absorption

d. myosin and actin

Answer 1

The answer is b. electrical signals and chemical neurotransmitters.

Electric signals include action potential. When neurons hit threshold and action potential is triggered, the Na+ channels open and Na+ ions enter the neuron. After the depolarization of membrane, Na+ channels inactivate. Consequently, the action potential is generated.

When an action potential reaches presynaptic terminal on a neuron, it will induce a release of neurotransmitters from the neuron. Neurotransmitters pass through the synaptic cleft and bind to the receptor on a postsynaptic neuron.