Prefixes and Suffixes cut = skin derm = skin melan = black seb = oil

HW: Describe how inflammation helps a wound heal. Page United Streaming – Skin 5mins United Streaming – Skin Cancer 4 mins B8FA283187A2&blnFromSearch=1&productcode=UShttp://player.discoveryeducation.com/index.cfm?guidAssetId=E3F2CB4B-2A7B-46DF-B615- B8FA283187A2&blnFromSearch=1&productcode=US United Streaming - Growing Skin Cells 4 mins

Do you know what is the largest organ in the human body? Hint: It makes up 12-15% of body weight

INTEGUMENTARY SYSTEM

Main structures: Skin, hair, nails skin houses nerves, sweat glands, blood vessels & hair follicles

3 Layers of Skin

1. Epidermis made up of epithelial tissue mostly dead cells provides a defense against harmful substances and injury

cells of epidermis contain a protein called keratin –gives skin its rough texture & waterproof quality contains the brown pigment melanin –absorbs uv rays

2. Dermis living cells contains sensory neurons, blood vessels, hair follicles, sweat glands & sebaceous (oil) glands Functions: regulation of body temp secrets waste products senses pressure and pain

contains collagen – fibrous protein; gives skin strength and elasticity sebaceous (oil) glands –lubricates skin, prevents excess H 2 O loss –kills bacteria sweat glands –gets rid of excess H 2 O and salts; regulating body temp

3. Subcutaneous Layer -made up of adipose (fat) tissue -provides insulation -energy reserve

Skin and Temp Regulation If the body becomes cold –the blood vessels constrict –decreases flow of warm blood near the body’s surface –reducing heat loss

If the body becomes hotter –Blood vessels dilate –Increasing flow of warm blood near surface or the skin –more heat loss

Sweat Gland and Temp When hot sweat glands contract releasing more sweat Sweat evaporates from the skin carrying heat away from the body

Skin Is Selectively Permeable | The skin is selectively soluble to fat-soluble substances such as vitamins A, D, E, and K, as well as steroid hormones such as estrogen. These substances enter the bloodstream through the capillary networks in the skin. Patches have been used to deliver a number of drugs in this manner. These include estrogen, scopolamine (motion sickness), nitroglycerin (heart problems), and nicotine (for those trying to quit smoking).

Components of the Skin (animation ) Skin Conditions Sun’s Effects on Skin Sweating (animation)

Skin Cancer Skin cancer is the most common type of cancer Melanoma is a malignancy of the skin in which the cells which give the skin it's color become cancerous

Skin Conditions (animation) Sun’s Affect on Skin