The central nervous system is controlled by the brain.
The central nervous system includes the spinal cord, the brain, and an
entire network of nerve fibers that run throughout the body. Unlike
the circulatory system which forms a closed loop, the nervous system has
"endings." This exercise will help students to visualize the pathways
of these nerves. The brain is an incredibly complex organ that is
the center of thought and all involuntary motions. The brain maintains
the body in working order by overseeing the functions of all organs and
body systems. The spinal cord is a soft, fluted column of nerve tissue
continuous with the lower part of the brain and is enclosed by the bony
vertebral column. This nerve tissue lies within the vertebral column;
the bone is there to protect the tissue. There are 31 pairs of spinal
nerves which emanate from the spinal cord. These nerves provide pathways
for impulses to flow throughout the body and to the brain.
- In this exercise the students will use the worksheet
to see how the central nervous system is connected with the brain.
Students should cut and paste yarn over the system. The darker
lines illustrate the 31 pairs of spinal nerves that begin at the
- Instruct the students to count the number of spinal nerves
first, and then direct them to trace the major ones with the yarn. Make
sure that the nerve paths end and are not looped.
- You may want to prepare a jello “brain mold” for students
to look at. Since the brain is considered the “nerve” center of the
body, this activity emphasizes the brain’s importance.
Ingredients for brain:
two 6 ounce boxes of gelatin mix (any
flavor, but peach or watermelon give a more realistic color)
1 ¾ cups boiling water
1 cup cold water
9 ounces fat free evaporated milk - don’t use any kind but fat
free or it will curdle
food coloring: about 15 drops each of red, green, and blue with
make a gray brain, but any colors will work
Before each use, wash the brain mold with warm soapy water.
Spray or smear the inside of the brain mold with a small amount
of vegetable oil.
Put the gelatin mix in a large bowl and add the boiling water.
Stir about 2 minutes until the mixture is dissolved.
Stir in 1 cup of cold water.
Add the evaporated milk and food coloring and stir well.
Adjust the color to your liking.
Pour the mixture into the brain mold, stopping about ¼
inch from the top.
Place the brain mold in a shallow bowl so it will sit level,
and refrigerate overnight or until firm.
To remove your brain, shake the mold until the gelatin loosens.
Place a flat plate upside down over the open side of the mold, then flip
the mold and plate together. Lift the mold off, leaving the brain
on the plate.