1. Neurons http://www.youtube.com/watch?v=vyNkAuX29OU
A neuron is a specialized cell that forms the basis of the nervous system. It is also referred to as a nerve cell.
They are able to transmit and gather electrochemical signals throughout the body (up to several feet or a few meters).
These signals are referred to as action potentials, nerve impulses or spikes.
Video: 1:56

2. Structure of a Neuron Node of Ranvier Nucleus Axon Myelin Sheath
Axon Terminals
Cell Body
Dendrite

3. Major Parts of a Neuron The Cell Body: it contains the:
nucleus (contains DNA),
endoplasmic reticulum,
mitochondria
Golgi apparatus
ribosomes
secretory bodies that contain the neurotransmitters.

4. 2) The Dendrites:
They are like small branches, which allow the neuron to connect to more than 1 neuron. They allow the neuron to talk to other cells or perceive the environment.
They receive the stimuli from the environment or from other neurons.
The dendrite converts the information into a neural impulse that is transmitted to the cell body.

5. 3) The Axon:
The longest fiber of the neuron which carries the neural impulse away from the cell body to the next connecting neuron, brain or other body part (effectors).
They can be very long, such as those that run from your toes to your spine.

6. 4) The Myelin Sheath
Myelin is made of a fatty substance that insulates the axon. This prevents the electrical current from leaving the axon.
This insulation acts to increase the rate of transmission of signals.
A gap (Nodes of Ranvier) exists between each myelin sheath cell along the axon. The signals jump from one gap to the next.
Multiple sclerosis (MS) is a chronic, disabling disease of the central nervous system. The disease causes inflammation, destruction, and scarring of the sheath (called myelin) that covers nerve fibers in the brain and spinal cord. As a result, electrical signals from the brain are slowed or blocked from reaching the eyes, muscles, and other parts of the body.

7. Neurons or nerve cells - Structure function and types of neurons