Where do most action potentials originate in a neuron?

• A. Node of Ranvier
• B. Axon hillock
• C. Dendritic spines
• D. Synaptic terminal

Answer: (B)

Verified step by step guidance

1. Understand the structure of a neuron: A neuron consists of dendrites, a cell body (soma), an axon, and synaptic terminals. Each part has a specific function in transmitting signals.
2. Learn about the axon hillock: The axon hillock is a specialized region of the neuron located at the junction between the cell body and the axon. It plays a critical role in initiating action potentials.
3. Recognize the role of the axon hillock: The axon hillock has a high concentration of voltage-gated sodium channels, making it the site where the threshold for an action potential is most likely to be reached.
4. Compare the axon hillock to other structures: While dendritic spines receive signals, the Node of Ranvier facilitates signal propagation along the axon, and the synaptic terminal transmits signals to other neurons, none of these structures are responsible for originating action potentials.
5. Conclude that most action potentials originate at the axon hillock due to its unique properties and location within the neuron.