The Nervous System

Impulses flash along individual nerves cells , or neurions.Each neuron has three main parts- a cell body , dendrites and an axon.
The difference between a dendrites and axon is that a dendrite is a nerve fiber that carries messages toward the cell body and a axon is a nerve fiber that carries message away from the cell body.
When an impulse reaches the tip of an axon, another nerve cells can't pick it up directly.That's because there is gap  between neurons. The gap is called a synapse.
There are three kinds of neurons- sensory, motors, and associative. The function of your sensory neurons is to collect information from stimuli and send it to your brain and spinal cord. A stimulus is anything that causes responses.
Your motor neutrons carry commands from your brain and spinal cord to your muscle and glands.
Associative neurons pass impulses from sensory to motor neurons. Most of the muscle in your brain are associative. They are only found in your brain and the spinal cord.
Blood sends oxygen and nutrients to neurons and also carries away waste made in nutrients.