A&P Neurophysiology Practice Test 2026 – Complete Exam Preparation

Myelination significantly affects the conduction speed of action potentials in neurons. When a neuron is myelinated, it is surrounded by a fatty substance called myelin, which is produced by glial cells. This myelin sheath effectively acts as an insulator, reducing the leakage of ions across the neuronal membrane.

As a result, the action potentials can jump from one node of Ranvier (gaps in the myelin sheath where ion channels are concentrated) to another in a process known as saltatory conduction. This jumping mechanism allows the electrical signal to travel much faster along the axon compared to non-myelinated fibers, where the action potential must traverse the entire length of the membrane continuously.

Consequently, myelinated fibers exhibit a dramatic increase in conduction velocity, which is essential for the rapid transmission of signals in the nervous system, especially in pathways involved in reflexes and coordinated movements. Thus, myelination plays a crucial role in enhancing neural communication and efficiency.