Neuron+-+EB

= = =Introduction= toc A mosquito lands on your arm. You freak out and swat it off immediately. If you did not have neurons your body would not have felt anything and the mosquito could have bitten you without you knowing! Nerve cells tell the body/ brain what is happening all around them. Without them you would not be able to feel, move, or even detect everyday things that happen all around you.

=Shape and Structure= A neuron is cell that sends electrical impulses throughout the body. A neuron’s body is a rounded or ball structure with a long tube called an Axon with branch like extensions called dendrites. All of these parts are shown in the picture on the right.

The axon’s job is to carry the impulse away from the cell body or soma. A axon has a tissue wrapping around it called a myelin sheath. This tissue wrapping helps quicken the speed of the impulse. An axon can be from 2 cm long to 40 in long! It can stretch from your spinal chord to the bottoms of your feet while the smallest neuron is about 4 microns wide.

The neurons body is the main area for sending and receiving impulses. It contains the nucleus which is kind of like the director of all activity.

The dendrites are kind if like the branches of a tree. They are at the top of the neuron and it is the receiver of the impulses that come from the other neurons. Once they receive the impulse, they send it toward the soma. The nerve impulse begins at the dendrite and moves toward the cell body the down to the axon and across the synapse

=The Synapse: Looking Closer=

It may look like neurons touch but they never touch! Now you are probably wondering how an impulse can just jump across a gap between two neurons. This area is called a synapse which is a fluid filled gap mainly found between dendrites of one neuron and axons of a different neuron.

The axon has a chemical in it called a neurotransmitter that carries the impulse across the synapse. Where the impulse will be accepted by the next neuron at a site called a receptor. They are also found at the end of axon and motor neurons, where they trigger the muscle fibers.

When the nerve impulse reaches the synapse a number of things can happen. One thing that can happen is the nerve impulse can be amplified or intensified. Another thing that can happen is that the impulse can be blocked altogether and sometimes the impulse will just go across normally.

You can think of a synapse as a road and the axon as a side walk. As a child or nerve impulse nears the road a crossing guard or neurotransmitters, stops traffic and helps the children cross the road safely. This process that is explained can also be referred to as the synaptic transmission. This should give you a good idea on what happens when an impulse passes through the synapse.

= media type="custom" key="27085824" width="80" height="80" = =More Than One=

In your body there are more than one type of neuron. There are actually three major types of neurons that make make up your nervous system. There is the sensory neurons, motor neurons, and interneurons.

Sensory neurons are found near and connects to the spinal cord. Motor neurons are located throughout muscles and interneurons are located in the brain and spinal cord. Interneurons can also be called association neurons. Doctors estimate that you have about 100 billion interneurons in the humans brain.

Each type of neuron has a specific job. The sensory neurons job is to pick up outer stimuli or outside activity and turn into an impulse that is sent to the brain. In the brain is where interneurons realize what is going on and sends a signal or impulse to your motor neurons that connects to your muscle so you can react.

For example. If you heard your ride to school beep the horn outside, you grab your backpack and walk outside. In just a simple activity like that all three neurons are working. Your sensory neurons in your ear pick up the sound ( stimuli ) and sends an impulse to the interneurons in the brain which realizes that its your ride to school. now that your brain knows that it’s your ride it sends an impulse to the motor neurons in your muscles which allows you to pick up your backpack and walk out the door.

=What is ALS?=

Have you ever heard of ALS? It is a diseases that happen when your neurons don’t work. It stands for Amyotrophic Lateral Sclerosis and it affects the nerve cells on the brain or spinal cord. The motor neurons that are between the brain to the spinal cord and spinal cord to your muscles eventually die from ALS which means that you would not be able to move. The picture on the right shows what the muscles look like once infected. Otherwise known as being paralyzed. There are also earlier symptoms that people notice too. They may notice or experience fatigue, poor balance, slurred words, a weak grip, or tripping when walking.

This disease mainly affects people around 60 years old. If you get it when you are younger than you probably inherited it from a relative. Not only does this disease paralyze you but it does kill many and only around 4% of people survive longer than 10 years.

This disease dates back to 1824 and has affected Lou Gehrig, a famous baseball player. After getting affected the disease soon became known as the Lou Gehrig disease. Lou Gehrig was a baseball player for the Yankees and holds the record for most grand slams in a career. In 1939 he made a speech at Yankee stadium where he retired leaving friends, family, and teammates weeping."Fans, for the past two weeks you have been reading about the bad break I got. Yet today I consider myself the luckiest man on the face of this earth," were Lou Gehrig's words on July 4. Just after two years after his speech he died at the age of 37.

Last year many people worldwide took part in the ALS ice bucket challenge where someone is nominated to dump a bucket full of ice on their heads to promote awareness.If you fail to dump ice on your head in 24 hours than you have to donate 100$ to the ALS association. Last year 653,000 people posted videos and they raised over 90,000,000. More than 122,553,700 people donated.

=Conclusion=

So it is your neurons to thank for small everyday things that you notice and feel. All three major types of neurons work hard everyday to keep you alert of the world around you. They are like the head guys of your body and when they don't work everything starts going downhill, so keep your body healthy because it does everything it can to keep you going. = = =References=

“The ALS Association Honors Lou Gehrig’s Legacy and 75th Anniversary of His Famous Farewell Speech.” Lou Gehrig. CMG Worldwide, 25 Apr. 2014. Web. 29 Jan. 2015. . “Biology for Kids: The Nervous System.” Ducksters. Technological Solutions.inc, 19 Dec. 2014. Web. 19 Dec. 2014. . “Neurons.” BrainPOP. BrainPOP, 2015. Web. 23 Jan. 2015. . Padilla, Michael J., et al. Prentice Hall Science Explorer. Boston: Pearson, 2009. Print. “What is ALS?” The ALS Association. The ALS Association., 2010. Web. 23 Jan. 2015. .