A neuron's axon ____.
A) is nearly always less than two millimeters in length
B) is usually completely covered in myelin from end-to-end
C) can either by myelinated or unmyelinated
D) usually ends in one "bulb," which physically connects to the next neuron

Question

Quizplus · Accepted Answer

A neuron's axon can either be myelinated or unmyelinated. Myelin is a fatty substance that covers and insulates parts of the axon, increasing the speed of neural impulses. However, not all axons are myelinated. In fact, some axons are deliberately left unmyelinated or only partially myelinated in certain regions to allow for more control over the transmission of signals.

A: False. The length of an axon can vary greatly depending on the type of neuron and the distance between the cell body and the axon terminal. Some axons can extend over a meter in length.
B: False. Myelin is not present on every part of the axon and is often interrupted by gaps called nodes of Ranvier.
D: Partially false. Axon terminals often end in synaptic knobs or boutons that release neurotransmitters into the synaptic cleft, but the physical connection between neurons is not always direct or through a single bulb.

A Neuron's Axon ____