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Nervous System: Top 10 Questions

December 2012

Thanks to Dr. Mary River, Neurologist, St. Alphonsus Hospital, Boise for the answers.

1: Why are nerves so important to our body?

Nerves are important to sense what's going on around you or within you. They tell your body where you are or what's around you. They tell your heart to speed up or slow down, your stomach when it's full, and they let your bladder know when you need to go to the bathroom. They are very important for every part of our functioning. (From Madeline at Anser Charter School in Boise)

2: What are nerves made out of?

Nerves are made out of axons like the wire that's in an electrical cord. There is an axon, or wire, that transmits the energy. The axon is covered with a coating called a myelin sheath, which protects it, and also keeps the electricity that is traveling along the axon from leaking out. (From Sophie at Anser Charter School in Boise)

3: When you get older, will you get more nerves?

You generally don't grow more nerves. You can heal an injured nerve if the injury is not too deep. If you injure the myelin sheath, or coating, of a nerve, you can regrow the coating. That's what happens when you bruise your funny bone. If you actually injure the axon of a nerve, most of the time, it doesn't re-grow. (From Olivia at Anser Charter School in Boise)

4: What does the nervous system look like?

If you look at the nervous system without any covering or with the naked eye, it would look whitish and a lot like firm jello. If you look at it microscopically, you would see bundles of nerves going up and bundles of nerves going down. It would look a lot like electrical cords bundled together. (From Henri at Cynthia Mann Elementary School in Boise)

5: How fast does it take for your brain to recognize that it got hurt?

The nerve fibers that sense discomfort or pain transmit messages very, very quickly in order to keep you from being hurt. If you touch a hot pan, those nerves transmit the message very quickly in order to get you to pull your hand away from the hot pan as soon as possible and avoid further injury. It would be in the range of 200 miles per hour. (From Harrison at Anser Charter School in Boise)

6: Why do nerves respond so fast?

Nerves respond quickly in order to keep you out of danger. If you step on a tack, then the nerve that you stimulated by doing that has to travel very quickly up to your brain to keep you from stepping on it further. Then a message travels back down allowing you to quickly step off the tack. This fast response helps keep you out of danger. (From Reid at Cynthia Mann Elementary School in Boise)

7: Why does a nerve not regenerate when it gets harmed?

Some nerves do regenerate. In the peripheral nervous system, the arms and legs, if a nerve is injured, it can sometimes re-grow if it hasn't been injured too severely. Most of the time, they don't. The number we are born with is the number that we get. You have to take good care of your nerves. (From Grant at Anser Charter School in Boise)

8: Does the nervous system create fear?

The nervous system doesn't create fear. It responds to fear. If you are walking in the woods and a bear shows up, your eyes see the bear. A message is then sent to the rest of the brain and the brain reacts, or responds, to that stimulation. (From Cooper at Anser Charter School in Boise)

9: What makes people ticklish?

There isn't a specific answer to that. The thought is that ticklish areas, like the bottom of your feet or under your arms, tend to be vulnerable. When they feel that something is going to happen, they withdraw for protection. (From Maddie at Trail Wind Elementary School in Boise)

10: Why does it hurt so much when you hurt your elbow?

It's not funny even though it is called the funny bone. The ulnar nerve is a nerve that goes to the pinky finger and half of the ring finger. It travels through a bony canal in the elbow. That groove of the canal in the elbow does not have a lot of protection. If you bang it, you actually bruise or shock the nerve. (From Wesley at Anser Charter School in Boise)


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