Final answer:
The myelin sheath, a lipid-rich insulating layer, surrounds the axon of a neuron, facilitating rapid and efficient electrical signal transmission and reducing energy consumption.
Step-by-step explanation:
The myelin sheath insulates the nerve cell from the surrounding environment, which increases the velocity at which impulses can travel along the axon. This layer is lipid-rich and formed by oligodendrocytes in the central nervous system (CNS) and by Schwann cells in the peripheral nervous system (PNS). It facilitates the transmission of electrical signals by preventing signal loss and allowing the nerve impulses to skip along the axon from one node of Ranvier to the next, thus enabling more rapid signal transmission compared to unmyelinated axons.
Axons ensheathed in myelin demonstrate higher speeds of signal transmission, consume less energy, and are better protected from cross talk compared with unmyelinated axons. This insulation is particularly crucial in longer axons, where the efficient relay of electrical signals over great distances is necessary for proper neural function.