Cell

Definition:
- The basic structural and functional unit of living organisms.

Facts
- The brain and spinal cord are made up of many cells including neurons.
- Neurons are cells that send and receive electro-chemical signals to and from the brain and nervous system.
- The Axon is a long extension of a nerve cell and take information away from the cell body.
- Neurons cannot regrow after damage


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What Kills Brain Cells?
-Concussions - Though most people have little control over it, concussions kill brain cells. Concussions are neuronal killers and should try to be avoided.Drugs – To state the obvious, -Drugs kill brain cells. Drugs such as ecstasy and cocaine kill brain cells because it wipes out the cells that make you feel good and are positive emotion and pleasure.
-Stress – Stress can be a positive thing in certain circumstances. It keeps people motivated to achieve their goals. But when stress gets to the point where you are having adrenaline rushes, your body produces the chemical, cortisol, which if you have to much of can kill brain cells.
-Junk Food – Eating junk food every once in a while is okay, but if that is all you eat you are in some trouble. Brain cells need nutrients to survive, and if you aren’t getting those nutrients, say goodbye to your brain cells!
-Alcohol – only alcoholics are to worry about killing brain cells. One beer won’t kill any but if you drink to much your brain will have a decrease in brain volume.

The Brain Cell consists of.....
The Axon - The long threadlike part of a nerve cell along which impulses are conducted from the cell.
The Cell Body - The part of a neuron containing the nucleus but not incorporating the axon and dendrites
The Dendrites - A short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body.
The Myelin Sheath - a layer of myelin insulating the axons of medullated nerve fibers
The Cell Nucleus - a part of the cell containing DNA and RNA and responsible for growth and reproduction.
The Synapse - A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.

References
http://www.enchantedlearning.com/subjects/anatomy/brain/Neuron.shtml
http://4mind4life.com/blog/2008/02/22/50-things-that-kill-brain-cells/