SKIN!

Table of ContentsDate Assignment Vocabulary Page

SKIN Epidermis, melanin, dermis

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:1) Epidermis2) Dermis

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

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!

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

– sweating• Vitamin D

– Is created in epidermis with the ultraviolet light from the Sun– Helps your body absorb calcium which is important for skeletal

system!

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

Brain Pop!

• As you watch the video about skin, think about all of the different jobs of the skin.

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)