Multiple Choice
In a neuron, the opening of sodium ($\mathrm{Na^+}$) gates typically leads to:
16
views
45. Nervous System
Neurons and Action Potentials
Struggling with General Biology?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
An action potential is self-regenerating because:
A
the refractory period prevents any further action potentials from occurring
B
the depolarization of one region of the membrane triggers the opening of voltage-gated Na$^+$ channels in adjacent regions
C
neurotransmitters are released continuously along the axon
D
the myelin sheath directly generates new action potentials
Verified step by step guidance1
Understand the concept of an action potential: An action potential is a rapid electrical signal that travels along the membrane of a neuron. It is initiated by the depolarization of the membrane, which occurs when voltage-gated Na⁺ channels open, allowing Na⁺ ions to flow into the cell.
Recognize the self-regenerating nature of action potentials: The key feature of an action potential is that the depolarization in one region of the membrane triggers the opening of voltage-gated Na⁺ channels in adjacent regions, allowing the signal to propagate along the axon.
Clarify why the refractory period is not the correct answer: The refractory period is a phase during which the neuron is temporarily unable to fire another action potential. While it ensures unidirectional propagation, it does not explain the self-regenerating property of action potentials.
Explain why neurotransmitter release is not the correct answer: Neurotransmitters are released at synapses to communicate between neurons, but they are not involved in the self-regeneration of action potentials along the axon.
Discuss why the myelin sheath is not directly responsible for generating action potentials: The myelin sheath insulates the axon and speeds up signal transmission by allowing action potentials to jump between nodes of Ranvier, but it does not generate new action potentials directly.
Related Videos
Related Practice
Neurons and Action Potentials practice set
Problem sets built by lead tutorsExpert video explanations