Understanding Nervous Impulse Conduction

What is the primary ion responsible for the depolarization phase of an action potential?

Which of the following best describes the role of myelination in nerve impulse conduction?

• It decreases the speed of nerve impulse conduction.

• It increases the speed of nerve impulse conduction.

• It has no effect on nerve impulse conduction.

• It prevents nerve impulses from occurring.

What is the term for the gap between two neurons where neurotransmitters are released?

• Axon

• Synapse

• Dendrite

• Node of Ranvier

Which neurotransmitter is primarily involved in muscle contraction?

• Dopamine

• Serotonin

• Acetylcholine

• GABA

During an action potential, what is the primary ion responsible for repolarization?

What is the effect of myelination on the nodes of Ranvier?

• It eliminates the nodes of Ranvier.

• It increases the number of nodes of Ranvier.

• It allows for saltatory conduction between nodes.

• It decreases the distance between nodes.

What is the threshold potential typically required to trigger an action potential?

• -90 mV

• -70 mV

• -55 mV

• 0 mV

Which ion channel is primarily responsible for the release of neurotransmitters at the synapse?

• Voltage-gated sodium channels

• Voltage-gated potassium channels

• Voltage-gated calcium channels

• Ligand-gated chloride channels

What is the role of neurotransmitters in synaptic transmission?

• They directly conduct electrical impulses.

• They serve as chemical messengers between neurons.

• They insulate axons.

• They degrade synaptic vesicles.

Which of the following best describes the refractory period of an action potential?

• A period when a neuron is hyperactive.

• A period when a neuron cannot fire another action potential.

• A period when a neuron is at rest.

• A period when a neuron is depolarizing.