What is myelin sheath?

The myelin sheath is a crucial structure in the nervous system, specifically composed of fatty substances that form a protective layer around the axons of neurons. This sheath serves several important functions: it insulates the axon, which enhances the speed and efficiency of electrical signal transmission along the nerve fibers. The insulating property prevents the loss of electrical current and allows the signals, or action potentials, to jump between nodes of Ranvier (gaps in the sheath), significantly speeding up the communication between neurons.

In contrast, other options describe different parts or mechanisms of a neuron. The protective layer surrounding the cell body pertains to the neuron’s soma and plays a different role in cell health and nutrient support. The segment of the neuron that receives signals refers to the dendrites, which are responsible for gathering incoming information. Neurotransmitters are chemical messengers that transmit signals across synapses but are not structural components of a neuron. Thus, the unique characteristics and functions of the myelin sheath are what make it vital for proper neuronal function and overall nervous system health.