What does myelination do to axons in the nervous system?

Myelination is a crucial process in the nervous system where axons, the long, slender projections of neurons that transmit electrical impulses, are coated with a substance called myelin. This myelin sheath acts as an insulating layer, which significantly enhances the speed at which electrical signals, known as action potentials, are transmitted along the axons.

The presence of myelin allows the electrical signals to jump from one node of Ranvier (gaps in the myelin sheath) to another, rather than traveling continuously along the entire length of the axon. This process, called saltatory conduction, results in much faster signal transmission compared to unmyelinated axons. This increase in speed and efficiency in communication between neurons is essential for the proper functioning of the nervous system, facilitating quicker reflexes and more effective information processing.

In contrast, the other options do not accurately describe the role of myelination. For instance, while myelination contributes to overall neuronal health and efficiency, it does not directly increase blood flow to neurons or form new neural connections. Myelination also does not reduce the size of neurons; instead, it enhances the functionality of axons by providing the necessary insulation for faster communication.