Quick! What's the

biggest organ in your body?

• In adults, the weight of your skin accounts for about 16% of your total body weight.

Sec. 5The Skin

Functions of skin

•Cover body & prevent water loss

Functions of skin

•Protect body from injury & infection

Functions of skin

•Regulate body temp.

Functions of skin

•Eliminate waste

Functions of skin

•Gather info about environment

Functions of skin

•Produce Vitamin D

2 main layers

of skin

epidermis dermis

Ever wonder what Ever wonder what makes makes different skin colorsdifferent skin colors??

• A pigment called melanin.

• More melanin in your skin cells makes your skin darker, less makes it lighter.

• Sitting in the sun can also cause more melanin to be manufactured in your skin cells. The result? A suntan.A suntan.

• As an adult, you may have more than 20 square feet of skin -- about the size of a blanket.

You are likely to shed some 40

pounds of skin in a lifetime.

• Right now there are over a million dust mites, microscopic critters invisible to the naked eye, on your mattress and pillow, chomping on the dead skin cells that fell off you last night!

Tastes like

chicken!

Yummy!

epidermisepidermis• outermost layer

• does not have nerves or blood vessels

• produces melanin= pigment that gives skin its

color

dermisdermis

• lower layer of skin

• contains: 1. nerves

2. blood vessels

3. sweat glands- perspiration

4. hairs- grow in follicles

5. pores= openings

4 habits that keep your skin healthy4 habits that keep your skin healthy

1. Eat properly

4 habits that keep your skin healthy4 habits that keep your skin healthy

2. Drink enough water

4 habits that keep your skin healthy4 habits that keep your skin healthy

3. Limit sun exposure-

• repeated exposure- leads to cancer= cells divide uncontrollably

4 habits that keep your skin healthy4 habits that keep your skin healthy

4. Keep skin clean & dry

• when oil glands became

clogged can cause acne

To help reduce the risk of skin cancer you should always remember

to apply sunscreen to your body.

• A sunscreen with an SPF of at least 15 is important to help protect your skin from dangerous burns and tans caused by the sun's ultraviolet rays.

• If you don't apply sunscreen on a regular basis, you are more likely to develop some form of skin cancer later on in your life.

• Lots of people think that you should only use sunscreen during the summer.

• However, to prevent aging caused by UV rays, you should wear sunscreen every day of the year-even if you're not really planning on being outside.

• Each year between 300,000 and 600,000 people are treated for skin cancer.

• The sun's UV rays are the strongest from 10 a.m. to 4 p.m.

Important Facts on Skin Cancer

Even animals are smart enough to protect themselves from the sun.

Did you know that elephants and hippos can get sunburned, too?  

They use dust or mud as a natural sunscreen!

• Melanoma is the most serious form of skin cancer. It is also becoming one of the most common types in the United States.

• Many dermatologists believe there is a link between childhood sunburns and malignant melanoma later in life.

You should be aware of unusual You should be aware of unusual skin conditions such as:skin conditions such as:

• change in size or color of darkly or irregularly pigmented growths or spots

• scaliness, oozing, bleeding, or change in a bump or nodule

• the spread of pigment from a bump or nodule or spot into surrounding skin

• a change in sensation such as itchiness, tenderness or pain.

HOMEWORK• Make a labeled 3-D model of a cross-section of skin• Include the following:

– Epidermis– Dermis– Blood vessels– Nerves– Hair follicle– Fat– Sweat gland– Oil gland– Pores – Hair

DUE: WED. 1/20

Fat

Model of

human skin