Nerve Impulses and Synapses Quiz

What is a nerve impulse?

• A chemical signal that travels along the neuron

• A thermal signal that travels along the neuron

• A mechanical signal that travels along the neuron

• An electrical signal that travels along the neuron

What is the resting potential of a neuron?

• The extracellular space is positively charged and the intracellular space is negatively charged

• The extracellular and intracellular spaces are negatively charged

• The extracellular space is negatively charged and the intracellular space is positively charged

• The extracellular and intracellular spaces are positively charged

What happens during depolarization?

• Sodium rushes into the neuron and reverses the charges

• Potassium diffuses out of the neuron

• The resting potential returns

• The sodium-potassium pump restores ion concentrations

What occurs during repolarization?

• Potassium diffuses out of the neuron and charge goes slightly further than the resting potential (hyperpolarization)

• Sodium rushes into the neuron and reverses the charges

• The sodium-potassium pump restores ion concentrations

• The resting potential returns

What is the role of the sodium-potassium pump?

• To release neurotransmitters across the synaptic cleft

• To restore ion concentrations to normal

• To open voltage-gated K+ channels

• To open voltage-gated Na+ channels

How does the myelin sheath affect nerve impulse conduction?

• It decreases the speed of the nerve impulse.

• It increases the speed of the nerve impulse by insulating the axon and facilitating saltatory conduction.

• It prevents the nerve impulse from occurring.

• It has no effect on the speed or quality of the nerve impulse.

What is the primary role of neurotransmitters in neuron communication?

• To create the myelin sheath around axons

• To serve as the metabolic fuel for neurons

• To facilitate the transmission of nerve impulses across the synaptic cleft

• To maintain the resting potential of neurons

What is the function of neurotransmitter receptors at the postsynaptic membrane?

• To synthesize neurotransmitters

• To degrade neurotransmitters

• To initiate a nerve impulse in the postsynaptic neuron

• To prevent the release of additional neurotransmitters

What is the significance of the synaptic cleft in neural communication?

• It is the site where myelination of axons occurs

• It is the gap that allows electrical signals to pass directly between neurons

• It is the space where neurotransmitters are released from the presynaptic neuron

• It is the location of the sodium-potassium pump

What is the term for the brief period after an action potential during which a neuron cannot be stimulated to fire another action potential?

• Threshold period

• Refractory period

• Depolarization phase

• Hyperpolarization phase