The myelin sheath is broken up by points known as the nodes of Ranvier or myelin sheath gaps. The myelin surrounding the neurons protects the axon and aids in the speed of transmission. Range dramatically in size, from 0.1 millimeters to over 3 feet long .Transmit information away from the cell body.

These myelinated axons transmit information much faster than other neurons. Some axons are covered with a fatty substance called myelin that acts as an insulator. The larger the diameter of the axon, the faster it transmits information. The axon is the elongated fiber that extends from the cell body to the terminal endings and transmits the neural signal. If the axon hillock is depolarized to a certain threshold, an action potential will fire and transmit the electrical signal down the axon to the synapses. When a signal is received by the cell, it causes sodium ions to enter the cell and reduce polarization. Possesses an internal polarization of approximately -70mV in a normal resting state.Acts as something of a manager, summing the total inhibitory.This action potential is caused by changes in ion channels which are affected by changes in polarization. If the sum of these signals exceeds a certain threshold, the action potential will be triggered and an electrical signal will then be transmitted down the axon away from the cell body. The axon hillock acts as something of a manager, summing the total inhibitory and excitatory signals. If the total strength of the signal exceeds the threshold limit of the axon hillock, the structure will fire a signal (known as an action potential) down the axon. The axon hillock is located at the end of the soma and controls the firing of the neuron. This results in the signal being transmitted down the axon. If the electrical impulses transmitted inward toward the cell body are large enough, they will generate an action potential. The neurons of the central nervous systems have very long and complex dendrites that then receive signals from as many as a thousand other neurons. Some neurons have very small, short dendrites, while other cells possess very long ones. These dendrites then receive chemical signals from other neurons, which are then converted into electrical impulses that are transmitted toward the cell body. Most neurons possess these branch-like extensions that extend outward away from the cell body. Have many dendrites, or only one dendrite.Dendrites are also covered with synapses. These tiny protrusions receive information from other neurons and transmit electrical stimulation to the soma. BSIP/UIG / Universal Images Group / Getty Imagesĭendrites are tree-like extensions at the beginning of a neuron that help increase the surface area of the cell body.

Diagram of neuron dendrite