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Don't Get Scrambled !
Your brain is the most important part of your body -- it is the part of you that makes everything else work. Therefore, if something happened to hurt your brain, a lot of other things in your body would stop working correctly, like your ability to see, hear, speak, learn... or anything else! Because it is SO important, the brain has developed its own protective devices to keep it out of trouble and keep your body working properly.
So, how does the brain protect itself?
There are several mechanisms involved in protecting the brain. The most obvious is your skull, which is the bone structure that holds your three pound (or approximately 1360mL) brain. Directly inside the skull, you will find what is known as the meninges, which consists of three protective layers between the brain and the skull. The outer layer, or dura mater, is hard and tough. The inner layer, or pia mater, is thin and delicate, surrounding the surface area of the brain. Between these two layers is the arachnoid layer (which looks like a spiderweb!!). Filling the arachnoid layer is a special liquid solution known as cerebrospinal fluid (CSF).
Picture courtesy of American Accreditation HealthCare Commission (http://www.nlm.nih.gov/medlineplus/ency/imagepages/19080.htm)
Where does CSF come from, and how does it move around?
The ventricular system in the brain consists of a series of chambers that are filled with CSF. These ventricles are lined with a very thin membrane, called the choroid plexus, which makes cerebrospinal fluid by filtering the necessary ingredients out of the surrounding blood vessels. The CSF moves through the specialized chambers in a very specific order: lateral ventrical --> third ventricle --> cerebral aqueduct --> fourth ventricle. For more information about the ventricular system, please check out the work of Mark Breedlove, et. al. at www.biopsychology.com.
Picture courtesy of the Centre for Neuro Skills (http://www.neuroskills.com/tbi/bcerebel.shtml) Why is the CSF so important?
The cerebrospinal fluid is a clear, colorless liquid, but that doesn't mean that it's useless; in fact, it works hard to protect your brain. It serves three main purposes:
1. Transportation: CSF carries sodium, glucose, and other vital nutrients from the blood into the brain (because your blood doesn't ever enter your brain!). It also keeps poisonous toxins out of the brain.
2. Flotation Device: Because of the concentration of salt and glucose in CSF, it allows the brain to "float." This aspect leads up to our last point:
3. Protection: CSF allows the brain to float, protecting it from potential injuries that would be caused by it banging around against the hard skull or other dangerous hard objects.
(For more information, please see: http://sleep25.vetmed.wsu.edu/KidsJudge2/PDF/2006/06_model_final_report_Ross.pdf )
It is important to remember, however, that the CSF can only do so much to protect your brain. When engaging in activities, sports, or games that might result in your head being hit with something hard, it is absolutely necessary that you wear a helmet to cushion any shock to the brain and prevent a concussion or traumatic brain injury. Such activities include bicycle riding, roller blading, ice skating, skateboarding, and soccer, among others. For more information on helmet use, please visit the website of the Snell Memorial Foundation, a non-profit organization which offers unbiased testing and ratings of helmet safety. They can be found at: http://www.smf.org/.
To try this experiment at home:
You will need: 2 eggs different colored markers about 2 cups of warm water about 15 teaspoons of salt 2 small ziplock bags (sandwich size) a yardstick paper a pen or pencil
Now, for the fun part:
First, use the makers to draw faces or write your name on each of the eggs. The eggs is supposed to represent your brain, so make it personal! Next, place each bag in a small ziplock bag. Seal one of the bags tightly. In the other bag, place approximately 2 cups of warm water and all of the salt. Stir and swish the salt into the water (being careful not to hurt your "brain") until the egg begins to float in the water. Once the egg begins to float, carefully seal the bag.
You'll want to have a friend or a parent with you for this part (but only so that they can hold up the yardstick -- you still get to do the fun stuff!). Take turns dropping the eggs, first the dry one and then the one in salt water (or CSF), from increasingly higher distances. Start at about four inches above the ground. If the egg survives the fall, try making it to 8 inches, or even a foot.
You'll notice that the egg without the salt water solution (like a brain without CSF) breaks from a much lower fall than the other egg (the brain with CSF). Use your paper and pen or pencil to make a chart of the distances each egg was dropped before it cracked. To be even more accuracte and scientific, you can try repeating the experiment several times over, recording your results each time. You'll begin to see just how much that cerebrospinal fluid really does protect the brain!!
Last, but not least: please remember to have fun and to be careful. Please involve a parent or another adult when trying the project at home, and ALWAYS remember to wear a helmet when your brain might be in danger!!
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