Test Your Sense of Touch Pg 72

Materials Needed:

thick card, pins, compass, colored markers, scissors, cloth, and ruler

Step 1:
Use the ruler and compass to draw three circles on the card, one inside the other.

The three circles should be 0.5 in (1.5cm) apart. The three circles form the three zones of your touch tester.

Step 2:
Cut out the large circle and color in the three zones.

If you want to have some friends to help, you could have more than one touch tester.

Step 3:
Ask a friend to blindfold you with a cloth.


Step 4:

Your friend should stick some pins in the central zone.

Make sure that the pin heads are level.

Step 5:

Ask your friend to press the pin heads gently against your arm. Have your friend to ask you how many pins you can feel. Try again with the pins stuck in the middle circle and the outer circle on your touch tester. Then test your palm and fingers.

I could only feel two, but there were three pins in the touch tester. When the touch tester was moved to my palm, I thought I felt three pins. I wasn't sure. Then when the touch tester was placed on my finger tips, I was sure that there were three pins.

Your sense of touch

Your sense of touch can be found all over the body. Your other senses are only located in specific parts. The reason for you can feel all over your body is that your sense of touch originates in the bottom layer of your skin called the dermis. The dermis is filled with tiny nerve ending which gives your brain information about what you feel.

The nerve endings in your skin can tell you if something is hot or cold. They can also feel if something is hurting you. Your body has about twenty differnt types of nerve endings that all send messages to your brain. However, the most common receptors are heat, cold, pain, and pressure or touch receptors. Pain receptors are probably the most important for your safety because they can protect you by warning your brain that your body is hurt!

Fun Facts

• You have more pain nerve endings than any other type.
• The least sensitive part of your body is the middle of your back.
• The most sensitive areas of your body are your hands, lips, face, neck, tongue, fingertips and feet.
• Shivering is a way your body has of trying to get warmer.
• There are about 100 touch receptors in each of your fingertips.
• Rattlesnakes use their skin to feel the body heat of other animals.

Other helpful sites

http://faculty.washington.edu/chudler/chtouch.html

http://faculty.washington.edu/chudler/pdf/mmsg.pdf

To view the Mini Lesson

Mini Lesson