What's Covering You? and why?

Weathersby, Dorothy                               Sherwood School
                                                  667-2042
                      

Objective:

The student will be able to describe the four functions of the skin.

Apparatus/Materials Needed:

1. Microprojector (optional)                 8. Construction paper
2. Microscopes (if available)                9. Toothpicks
3. Overhead projector                       10. Plastic gloves
4. Skin slide                               11. Paper cups
5. Model of the skin                        12. Water
6. Transparency of the skin                 13. Pepper
7. Crayons

Introduction:

      The skin is an organ consisting of tissues structurally joined 
together to perform specific activities (functions).  The four main
functions are: (1) Protection: The skin covers the body and provides
a physical barrier that protects underlying tissues from physical
abrasion, bacterial invasion, dehydration and ultraviolet radiation.
(2) Maintenance of body temperature: The production of perspiration
by sweat glands help to lower body temperature back to normal.  
(3) Excretion: Not only does perspiration assume a role in helping to 
maintain normal body temperature, it also assists in excreting small 
amounts of water, salts and several organic compounds.  (4) Perception 
of stimuli: (sensitivity) The skin contains numerous nerve endings and 
receptors that detect stimuli related to temperature, touch, pressure 
and pain. 

Procedure: 

      Before you introduce lesson to your students, make sure the 
students have one of each of the following: paper cup, toothpick, 
and a plastic glove.  Pour one half cup of water in each cup and
sprinkle pepper in the water.  Write the title "What's Covering You?
and Why?" on the blackboard.  Ask the students if they can figure out
what is going to be discussed.  Hopefully, "the skin" will be their
response.
      Use the following phenomenological approaches to teach the four
functions of the skin.

1. Protection: Have the students put on one glove and stick their
fingers into the water with pepper.  Have the students pretend the
glove is representing their skin.  Now have the students take their
fingers out of the water after a few seconds.  Ask what happened?
Have the students leave on their glove while you discuss what happened.  
2. Maintenance of body temperature: By the time you finish discussing 
function one, the students hand with the glove should be warm and 
somewhat sweaty.  Have the students take off the glove and wave that 
hand in the air. Now ask what do they feel?  Discuss.  3. Excretion: 
Function two and three are somewhat alike.  Include in your discussion 
that excretion is more than letting out a waste.  Have the students 
express their opinion of excretion and the taste of perspiration.  
4. Perception of stimuli (sensitivity): Have the students take the 
toothpick and gently rub it on their arm.  Ask what they feel? Now, 
have the students pinch themselves (gently) and turn to the person next 
to them and touch them.  Ask what do they feel? Discuss response. 
     After you discuss the four functions, show pictures of the skin
using the overhead projector, microprojector and model.  Pointing
out the sweat gland.  Inform the students that they have two sections
within the skin; the outer (epidermis) and inner (dermis) section.
Within the sections are other layers.  As independent practice have
the students take a sheet of paper and fold it to make four squares.
Then have students use crayons to draw a picture representing each
function.  After completing the activity, pass out colored sheets of 
the skin showing the outer and inner sections of the skin. 

Vocabulary

protection           perspiration
excretion            bacteria
gland                temperature