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The Skin. By Neasia Clevenger and Lysia Cook. Definition. The thin layer of tissue forming the natural outer covering of the body of a person or animal. The skin is part of the integumentary system along with hair and nails. It is the largest organ in the body. The Main Functions.
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The Skin By Neasia Clevenger and Lysia Cook
Definition • The thin layer of tissue forming the natural outer covering of the body of a person or animal. • The skin is part of the integumentary system along with hair and nails. • It is the largest organ in the body.
The Main Functions • It protects us from germs and the elements. • Is an aide in regulating body temperature. • Allows us to feel the sensations of touch, cold, and heat.
Other Uses • It absorbs the sun's ultra violet light to create small amounts of vitamin D, which helps to build healthy bones and teeth. • When the skin gets wet, the first layer absorbs as much as it can and wrinkles to preserve space. • if it did not wrinkle, your skin would expand too much and break open
The Layers Of The Skin The 3 main layers of skin are the • Epidermis • Dermis • Hypodermis
The Epidermis • The epidermis is the outermost layer of skin which is made up of dead cells. • This is the layer that can be seen by yourself and others. • It’s about as thick as a piece of paper, but thickens on the hands, fingertips, and soles of the feet. • It supplies us with a waterproof barrier by absorbing water when we touch it.
The Dermis • The dermis is the second layer of skin. • It has many fibers called collagen that provide strength and allow skin in bend without tearing. • New skin cells are constantly being produced in this layer. • It contains the sturdy connective tissue, sweat glands, and hair follicles.
The Hypodermis (Fat) • The hypodermis lies between the dermis and underlying tissues and organs. • It’s made up of body fat and more connective tissue. • Acts as an energy and heat reserve for us.
Inside the Layers: Hair Follicles • Hair follicles are the growth place of the hair on your body • Every hair you have grows from a live follicle, with it’s root being in the hypodermis. • They are connected to nerve endings, allowing you to sense the slightest touch.
Inside the Layers: Hair • Only your lips, soles of your feet, and palms of your hands are really hairless. • The hair on our body acts as an insulator. • You get goose bumps when you’re cold because the hair is rising and trying to form a barrier to trap warmer, still air next to your skin.
Inside the Layers: Sweat glands and Pores • Sweat glands secrete water, salt, and other waste products to cool down the body as it evaporates. • You begin to sweat if you get too hot or if you’re stressed. • Sweat glands are all over your body, but are abundantly placed on your palms, soles of feet, forehead, and underarms. • Apocrine glands are different from normal sweat glands and give off an odor
Inside the Layers: Blood Vessels • Blood vessels help to keep your body at a regular temperature. • When the outside temperature drops, the vessels constrict themselves to lessen the flow of blood to your skin, which keeps you warmer. • As the outside temperature rises, the vessels dilate t help you keep cool.
Inside the Layers: Lymph Vessels • These vessels are a network similar to blood vessels, through which lymph drains from the tissues and into the blood. • Lymph is a colorless fluid containing white blood cells that bathes the tissue and acts as a cleanser. Lymph Vessel
Inside the Layers: Sebaceous Glands • The sebaceous glands secrete sebum, an oily substance that acts as a natural moisturizer and protective layer to your skin. • The glands are mostly located near the base of hair follicles. • These glands are the actual cause of acne. When the hair follicles get plugged with their oil, sebum, a pimple forms.
Inside the Layers: Keratinocytes • Keratinocytes are epidermal cells that produce keratin. • Keratin: A fibrous protein that gives are skin strength
Inside the Layers: Melanocytes • Melanocytes are the cells that absorb small amounts of UV light to protect your skin. • They create melanin, which plays a role in the color of your skin. • The more melanin you have, the more melanocytes you have, which gives you more protection from the sun.
Why are you the color you are? • Melanocytes: a cell in the layer of the epidermis that produces melanin • Melanin is the thing that gives you the pigment you have. • The more melanin, the darker your skin and hair. • Your color, or the amount of melanocytes, you’ll have are determined by your parents traits and backgrounds.
Sensory Reception • The skin is filled with sensory receptors that sense pain, heat, cold, touch, and pressure. • The number of skin receptors vary in number all over the body. • For example, the hands have less receptors for temperature than the head. • Nerves travel through out your body and, in the skin, are attached to hair follicles in and throughout the dermis.
Video • http://www.youtube.com/watch?v=yKAzVC0WcmI
How to Care for Your Skin • Protect yourself from the sun. • Limit the time you take to bathe, avoid strong soaps, and shave carefully. • Eat a healthy diet. • Don’t smoke, although this doesn’t apply to people are age, it can cause serious effects on our skin. • Managing stress.
Sun Damage • Ultra violet sun rays penetrate deeply in your skin and kill living cells. • Excessive tanning can damage skin by causing • Freckles • Sunspots • Age spots • Skin cancer • Thinking you have a natural tan (not caused by a tanning bed) will protect you from sun exposure is actually wrong. • A natural tan is equivalent to an SPF of 4. • The reason that sunburn is red is because blood flow is increased and sent to the burned areas, making it read and warm to the touch.
Hygiene • Don’t take excessively long showers often. • Avoid powerful soaps. • Doing these things can strip your skin of natural oils in needs and make it dry out. • Shave carefully and in the direction the hair grows. • Pat dry after showers to allow some moisture to be held by the skin. • Doing these things will ensure your skin stays moisturized and is still clean.
Eat a Healthy Diet • Eating fruits, vegetables, whole grains, and lean proteins has been thought to decrease the amount of acne you have. • A diet high in vitamin C and low in unhealthy fats and processed/refined carbohydrates will promote younger looking skin. • Eating healthy will simply make you look and feel better.
Don’t Smoke • Smoking causes the tiny blood vessels in the out layer of our skin to narrow. • As they become narrow, the skin is deprived of oxygen and nutrients that are important in having healthy skin. • Smoking also damages elastin and collagen, which are the fibers that give your skin strength and elasticity. • Even being exposed to second hand smoke can be damaging.
Manage Your Stress • Constant stress can make your skin more sensitive and more prone to acne breakouts. • It is important to have a healthy state of mind by taking steps to manage stress. • Setting reasonable limits and not taking on more than you can accomplish are easy ways to do so.
Review Worksheet: Students come up and put the answers they got.
Worksheet Answer Key Pore Melanocytes & Keratinocytes Sebaceous Gland Epidermis Dermis Blood & Lymph Vessels Hypodermis Hair Follicle Sweat Gland
Bibliography • Allen, Katy Z. Human Body Systems and Health. Austin, TX: Holt, Rinehart, and Winston, 2005. Print. • Colombo, Luann. Uncover the Human Body. San Diego, CA: Silver Dolphin, 2002. Print. • "Get Inside Your Skin." WebMD. WebMD. Web. 05 May 2012. <http://www.webmd.com/healthy-beauty/healthtool-inside-your-skin>. • Rooney, Anne. Human Body Works: The Nervous System, the Skin, the Senses. Chicago: World Book, 2007. Print. • "The Skin (Human Anatomy): Picture, Definition, Function, and Skin Conditions." WebMD. WebMD. Web. 05 May 2012. <http://www.webmd.com/skin-problems-and-treatments/picture-of-the-skin>. • Staff, Mayo Clinic. "Skin Care: 5 Tips for Healthy Skin." Mayo Clinic. Mayo Foundation for Medical Education and Research, 06 Dec. 2011. Web. 05 May 2012. <http://www.mayoclinic.com/health/skin-care/SN00003>. • "Touch." ThinkQuest. Oracle Foundation. Web. 05 May 2012. <http://library.thinkquest.org/05aug/00386/touch/sensoryreceptors.htm>.