What are the gaps in myelin sheath called that allow faster action potential conduction?

The gaps in the myelin sheath that allow for faster action potential conduction are known as the Nodes of Ranvier. These nodes are small, exposed sections of the axon located between segments of myelinated sheath. In myelinated neurons, the myelin acts as an insulator, significantly speeding up the transmission of electrical signals along the axon through a process called saltatory conduction.

At the Nodes of Ranvier, the axonal membrane is exposed, allowing ions to flow in and out of the neuron, which is essential for generating action potentials. Instead of the impulse having to travel continuously along the entire length of the axon, it "jumps" from one node to the next. This jumping mechanism results in much quicker signal propagation compared to unmyelinated fibers, where the action potential must traverse the membrane continuously.

The other options, such as synapses, dendrites, and axon terminals, refer to different aspects of neuronal structure or function. Synapses are junctions where communication occurs between neurons, dendrites are the branches that receive signals from other neurons, and axon terminals are the endings of an axon where neurotransmitters are released. Each plays an important role in the overall function of a neuron but does