The myelin sheath coats the axon of a neuron and speeds up the transmission of messages. Myelin is a fatty coating that is unable to perpetuate the action potential signal. As a result, the signal jumps over the myelinated areas, bypassing much of the axon and speeding up transmission. This process is known as saltatory conduction.

The axon is the long, slender projection of a neuron that conducts electrical impulses away from the cell body. Dendrites are the branched projections of a neuron that recieve electrical stimulation from synapses and convey them to the cell body. The soma is the cell body of the neuron that contains the cell nucleus

Myelin is a white, fatty compound that surrounds the axons of white matter neurons. Its purpose is to increase the speed of an action potential.

At rest, there is a high concentration of sodium (Na⁺) outside the neuron and a high concentration of potassium (K⁺) inside the neuron. During an action potential, the gated channels for sodium open and, because there is such a difference in concentration, the sodium rushes into the axon. This makes the axon much more positive in charge. This positivity propagates along the axon until it reaches the end of the axon, where it triggers release of neurotransmitters into the synapse.

The depolarization of the neural axon during an action potential is driven by an influx of sodium ions, entering through voltage-gated sodium channels. Following this stage, voltage-gated potassium channels are stimulated, allowing potassium ions to exit the axon and causing hyperpolarization. The sodium-potassium pump then restores the ions to their original positions in preparation for the next action potential, known as repolarization.

Neurotransmitters are chemical substances that travel across synapses in the nervous system. Acetylcholine, dopamine, epinephrine, and GABA are all widely-studied neurotransmitters. Glucose, however, is a monosaccharide used for energy in the body. It serves no purpose as a neurotransmitter.

Glial cells are located in the nervous system, and serve as support and protection for the neurons. Schwann cells, oligodendrocytes, astrocytes, and ependymal cells are all examples of neuroglia.

After crossing the synapse, neurotransmitter molecules bind to receptors on the postsynaptic neuron, initiating an excitatory signal (EPSP). The signal then travels through the dendrites to the cell body, where it becomes an action potential based on the degree of stimulation from other EPSP signals. After traveling through the cell body and down the axon hillock, the signal is sent out by the axon to the axon terminal, or synaptic terminal. There, synaptic vesicles containing neurotransmitters are released into the synaptic cleft (the space between two neurons). Synaptic vesicles fuse with the membrane at the axon and release neurotransmitter into the synaptic cleft. The neurotransmitters diffuse toward the postsynaptic neuron and bind to receptors to begin the process again. Once the signal reaches an effector organ, the neurotransmitters can elicit their ultimate effect.

Agonists are chemicals that mimic the action of a neurotransmitter. Agonists bind to the same receptor sites as neurotransmitters, but cause their own unique biological responses. Agonists activate the receptors to which they bind.

Efferent neurons are responsible for relaying information from the central nervous system to the muscles or glands. These signals allow for movement. 

The Myelin Sheath is a fatty substance that covers the axon and helps speed up impulses. A neuron is a nerve cell. Dendrites are the message receiving part of a neuron, and axons are the message sending part. A synapse is the gap between the terminal buttons of the axon of one neuron and the dendrites of another neuron. Soma is a term synonymous with cell body.