1. SKIN!

2. Table of Contents Date Assignment Vocabulary Page SKIN
Epidermis, melanin, dermis

3. SKIN – Your epidermis is showing!
The skin is the largest organ in the human body
We gain a lot of information from the environment outside of our bodies by sensing through our skin
Has two layers of tissue:
Epidermis
Dermis

4. EPIDERMIS Top layer of skin tissue
Cells on the top of this layer are dead
they rub off every time you scratch any part of your skin
New cells are produced at the bottom of the epidermis layer
Cells in the epidermis produce a chemical called melanin
Melanin gives color to the skin
more melanin = darker color

5. DERMIS Layer of tissue under the epidermis
Much thicker than the epidermis and contains the blood vessels, nerves, oil and sweat glands
3 million sweat glands!

6. What is the purpose and function of skin?
There are 5 functions for your skin:
Protection
against disease, keeps water in
Senses
senses what is going on around the body
Helps control body temperature
sweating
Excretion (removal) of wastes
Vitamin D
Is created in epidermis with the ultraviolet light from the Sun
Helps your body absorb calcium which is important for skeletal system!

7. Injuries Injuries to your skin like:
Scratching
Burning
Ripping
These injuries may remove the epidermis layer and new cells may not be created
This will make it easier for bacteria and viruses to enter your body, and an infection may occur

8. Brain Pop!
As you watch the video about skin, think about all of the different jobs of the skin.

10. Activity:
1) On a piece of paper in your lab section, write down 3 observations about the epidermis on your hands
2) One volunteer for each group will place a small plastic bag over his/her hand and another group member will use tape to keep the bag closed
3) Start working on your worksheet for today and after 5-6 minutes and look at the hand with the bag. Please answer the following questions under your initial observations:
4) Questions:
What formed inside the bag?
Where did this substance come from?
Why is it necessary for this substance to form, even though you are inactive (for example not jumping around in P.E. class)