Transmission of Nerve Impulse: Action Potential

What is the resting membrane potential of a neuron?

• -70 millivolts

• -50 millivolts

• -30 millivolts

• -90 millivolts

Describe the process of depolarization during an action potential.

• Depolarization is the phase where the membrane potential remains constant and does not change.

• Depolarization occurs when potassium ions exit the cell, making the membrane potential more positive.

• Depolarization is the phase where the membrane potential becomes more negative due to the influx of sodium ions.

• Depolarization is the phase where the membrane potential becomes less negative due to the influx of sodium ions.

What is the role of voltage-gated sodium channels in the generation of an action potential?

• Voltage-gated sodium channels allow the efflux of sodium ions

• Voltage-gated sodium channels allow the influx of sodium ions, leading to depolarization and the generation of an action potential.

• Voltage-gated sodium channels are only involved in repolarization

• Voltage-gated sodium channels prevent the generation of an action potential

Explain the concept of the threshold potential in relation to action potentials.

• The threshold potential is the membrane potential that must be reached to trigger an action potential.

• The threshold potential is the potential at which a neuron stops firing action potentials.

• The threshold potential is the potential at which a neuron becomes hyperpolarized.

• The threshold potential is the maximum potential a neuron can reach.

How does the refractory period contribute to the propagation of action potentials?

• The refractory period enhances the speed of action potential propagation

• The refractory period allows for immediate re-excitation of a region

• The refractory period contributes to the propagation of action potentials by ensuring unidirectional flow and preventing immediate re-excitation of a region.

• The refractory period has no impact on action potential propagation

Discuss the significance of the sodium-potassium pump in maintaining the resting membrane potential.

• The sodium-potassium pump is only active during cell division

• The sodium-potassium pump only transports potassium ions across the cell membrane

• The sodium-potassium pump is essential for establishing and maintaining the resting membrane potential by actively transporting ions across the cell membrane.

• The sodium-potassium pump has no role in maintaining the resting membrane potential

What is the all-or-none principle in the context of action potentials?

• The all-or-none principle means that action potentials can fire partially.

• Action potentials always propagate bidirectionally along the axon.

• Action potentials can be initiated by any stimulus regardless of intensity.

• The all-or-none principle in the context of action potentials refers to the fact that an action potential will either fire completely or not at all.

Compare and contrast the speed of conduction between myelinated and unmyelinated axons.

• Both myelinated and unmyelinated axons have the same conduction speed.

• Unmyelinated axons have faster conduction speed than myelinated axons.

• Myelinated axons have faster conduction speed than unmyelinated axons.

• Myelinated axons have slower conduction speed than unmyelinated axons.

What is the role of the nodes of Ranvier in saltatory conduction?

• Nodes of Ranvier are responsible for generating action potentials

• Nodes of Ranvier slow down the propagation of action potentials

• Nodes of Ranvier prevent the propagation of action potentials

• Nodes of Ranvier facilitate the rapid propagation of action potentials by allowing for saltatory conduction.

Explain the concept of synaptic transmission and its connection to the propagation of nerve impulses.

• Synaptic transmission is not related to nerve impulses

• Synaptic transmission is essential for the propagation of nerve impulses as it allows for the communication between neurons, enabling the signal to travel from one neuron to another across synapses.

• Propagation of nerve impulses does not involve synaptic transmission

• Synaptic transmission occurs outside of neurons