The gaps in the myelin sheath are called nodes of Ranvier.
Myelin is a fatty substance that surrounds and insulates nerve fibers, allowing electrical impulses to transmit quickly and efficiently along the nerve cells. The myelin sheath is not continuous; it has periodic gaps where the axon is exposed. These gaps, known as nodes of Ranvier, play a crucial role in the conduction of nerve impulses.
When a nerve impulse travels down an axon, it jumps from one node to the next, a process called saltatory conduction. This jumping mechanism greatly increases the speed at which impulses can travel compared to unmyelinated fibers. The presence of the nodes of Ranvier is essential for the proper functioning of the nervous system, facilitating rapid and efficient communication between neurons.