Skin+Cells+-+AD

= Introduction = toc It’s 80 degrees out, and you're at the beach. You're sitting there in the sun without sunscreen. Do your burn, or do you tan? Whichever happens to you, they both have a lasting effect. The amount of time you sit in the sun without sunscreen can affect the color of your skin, and the amount of time you have sunscreen on can affect it even more. Sunscreen will stop you from burning and getting some of the deadliest diseases around. You need to be able to take care of your own skin, though. If you make the choice to get a tattoo you probably don’t know the harm it actually does to your skin. Your skin with three layers and tons of tissue produces new cells through processes and keeps you as healthy as possible, but you need to care for your skin too. How do you do that?

Structure
Your skin has three layers. The **epidermis** is the top layer (on the outside). The epidermis is made up of cells with a **basal layer**. This basal layer forms new cells, through a process called **cell division**. Cell division is when your cells divide and start to move up to the surface of your epidermis. The cells take an estimated time of 1.5 months to reach the surface. As your cells are moving towards the surface they will flatten and form **keratin fibres**. Keratin is a fibrous protein. By the time your new cells reach the outermost part of your epidermis, they will be dead. The dead cells are worn away by another process called **friction**. Friction is the process of one thing rubbing against another. Your **dermis** is the inner layer of your skin. Your dermis is filled with a bunch of different tissues and structures. Here are a few:
 * **Connective tissue** – packs and binds the other structures in the skin.
 * **Elastic fibres** – make the skin resilient.
 * **Capillaries**– tiny blood vessels.
 * **Muscle fibres** – to move the position of the hairs.
 * **Sensory cells** – to sense touch, pressure, heat, cold and pain.
 * **Nerve fibres** – to activate muscles and glands and relay messages from the sensory cells to the brain.
 * **Pigment cells which produce Melanin**- a very dark pigment.
 * **Sweat Glands**- which open onto the surface as pores
 * **Hair follicles** – pits in the epidermis in which hairs grow.
 * **Sebaceous glands** – produce oil to keep hair follicle free from dust and bacteria, and to help to waterproof the skin.



Function
Your skin has many important tasks and functions to do. One function is to control the body temperature. Your body needs to have a normal temperature of 98.6 degrees fahrenheit, (37 celsius). Whatever your surroundings are, your body temperature needs to be 98.6 fahrenheit. This is controlled by a **feedback system**. The feedback system, sends messages from the **temperature sensitive receptors** in the skin to the **hypothalamus**. From the hypothalamus, messages are sent to different parts of the body including back to the skin to keep heat in or lose the excess heat. If the body is to cold then small muscles cause the hair to raise. The hair raising confines the air giving the look of goose bumps. In this case, air is an insulator keeping in as much heat as possible. The amount of heat loss depends on the amount of blood flowing through the skin. Click this link to learn more about some of the other important functions that your skin does (or watch the video): Some of the topics the video and link will cover are how the skin...
 * Keeps out infections
 * Is a waterproof barrier
 * Protects delicate tissues underneath
 * Mends itself when damaged

http://www.abpischools.org.uk/page/modules/skin/skin3.cfm?coSiteNavigation_allTopic=1

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Why Do We Need to Wear Sunscreen?
Sunscreen is important for the human body because it protects the skin from **ultraviolet rays**. There are two different types of sunscreen. There is physical sunscreen and chemical sunscreen. Both types of sunscreen protect the body from sunburn, aging, and skin cancer. The two types of sunscreen are physical and chemical. **Physical sunscreen** acts as a barrier, causing the sun to “bounce” off you. **Chemical sunscreen**, absorbs sun rays. To have the strongest effect of sunscreen, you need 30 **SPF+**. SPF is the measure of how much sun will be blocked before a single UV ray starts to hit. Some skin doesn’t burn and only tans, but sunscreen is still important. Your skin isn’t immune to the effects of the sun.

What Is the Science Behind Skin Color?
The science behind skin color could seem quite confusing, but it’s not. Skin color comes from a **pigment** in your skin called **Melanin**. Melanin gives the color to your skin and hair. Melanin comes from the cells called **melanocytes**. There are 2 types of the melanin pigment. There is **EU Melanin** and **Pheomelanin**. U melanin is the pigment that gives the color of brown skin tone. Pheomelanin is what gives the reddish brown of freckles. The amount of melanin you have in your skin alters how badly your skin acts to the sun. Depending on the amount of melanin you have in your skin, you may either badly burn or just lightly tan. No matter what type of melanin and how much of it you have, you must still wear sunscreen. UV rays can damage the **DNA** within our melanin cells. That’s what causes the skin to burn. If the sun's damage to skin is severe enough, it can lead to **Melanoma**. Melanoma is a deadly type of cancer caused in the skin when exposed to much direct sun with no protection. Melanoma is caused over a stretch of time.

What Makes a Tattoo Permanent?
Have you ever wondered what actually makes your tattoo permanent, if you shed your skin and get new skin cells everyday? Getting a tattoo requires the pigment to go further into your skin then just the outer layer. The outer layer of your skin is the only skin that gets shedded. When the needles, loaded with dye are put into the skin, they punch through the epidermis. Since the needles are going through the epidermis, the dye is being pushed through to the dermis. To learn more about how a tattoo fully develops, becomes permanent and shows its color through your skin take a look at this video:
 * 1) Macrophages eat the invading materials
 * 2) Macrophages carry dye into the Lymph Nade
 * 3) Not all dye is carried to the Lymph Nade, some dye stays in the Dermis
 * 4) There is no where for the dye in the Dermis to go and that causes the dye to be visible through the epidermis
 * 5) Tattoos will slowly fade naturally because of the bodies reaction to the alien pigment particles
 * 6) Tattoo dye will never fade completely causing it to be in your skin for life

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