What is a "neuron"?
A neuron has the following parts to it: a nucleus and ribosomes which make proteins. That's where the RNA is. The DNA speaks to the RNA and there is a message that's sent, and proteins are made. So all those are in the cell body, in their own little cell bodies. Now, it has processes which are called dendrites, which are short processes, and they may have a hundred of them in a big neuron. That's the receiving end of the neuron. So a dendrite might have connections with fifty other neurons, and it's all going to be with connections to that dendrite. And then it has a part that goes to other neurons or to other structures. That's the axon. So there is the cell body with it's dendrites, which is the receiving part of the neuron, and it has an axon. It only has one axon. It has many dendrites. That one axons is going to go somewhere. Now if it is a motor neuron, it's going to go out to the muscle. If it is in the brain, it may go to other neurons, or it may go to the basal ganglia, or it may go to the medulla oblongata, or it may go elsewhere, but basically it is going to carry that neuron's message somewhere. Now, the axon has the neurotransmitter in it. It's made in the cell body, but it's going to carry it to wherever it wants to go. The dendrite is receiving. The axon is also going to have what we call the action potential. It's going to propogate an electrical signal. It is the axon that has myelin in it. Dendrites don't have any myelin. So the axon can be covered with an insulator so it can move faster, essentially, and there are axons that don't have myelin. They move slower. So there are different types of axons. Quite clearly, the axon is the nerve.
