A neuron is a nerve cell that is specialized to carry messages through the body by transmitting signals to the nervous system.There are 100 billion neurons in our nervous system. Neurons come in all different shapes and size, the biggest neuron is 3 meters long and the smallest is only 4 microns wide. Neuron are very similar to the other cells in the body, as that may be they actually are very different. The neurons contact with each other by using the electrochemical process. Also neurons have elaborated with dendrites and axons. The dendrites deliver info to the cell and look like spikes coming out of the cell body. And the axons take the information from the cell body and are hard to classify from the dendrites. The axon conduct electrical messages that is called action potentials. Normally when the neuron is at rest the positive charges are outside and the negative charges are inside of the axon of a cell and it's not not sending a signal which is resting potential. When its at rest the potassium ions cross through the membrane, but the chloride ions and sodium ions have a difficult time going through. A resting membrane potential of the neuron is 70mv. There are relatively more sodium ions outside the neuron and more potassium ions inside that neuron. But then when it increases to about 50mv its is called action potential.
http://faculty.washington.edu/chudler/ap.html
http://faculty.washington.edu/chudler/cells.html
http://webspace.ship.edu/cgboer/theneuron.html
