1. OBJ: Given video, notes, activity sheet SWBAT describe the structures and functions of the skin with 70% accuracy. BRING IN TEXTBOOK DN : Hand-in VKS Lab write-up and scantron. Video: The SKIN ACT: Introduction to the Skin (Notes) Text, read p. 30-35; Work on iPad (eSpark Assignment) HW: Complete The Skin Booklet; Work on SMSD Review Sheets; SMSD Exam, Feb 25; Winter Recess HW, NYSSAE 2008 Exam (on scantron, due Monday, Feb 23).

2. SKIN NOTES SKIN FUNCTION –Covers and protects from injury, infection, water loss –Regulates body temperature –Removes waste (perspiration) –Collects environmental information –Produces Vitamin D –LARGEST ORGAN IN THE HUMAN BODY Skin consists of: epidermis – outer layer dermis – inner layer

3. SKIN NOTES EPIDERMIS (OUTER LAYER): No nerves, no blood vessels Upper Epidermis (dead cell layer) – consists of dead cells which shed after two weeks Lower Epidermis (skin producing factory) – consists of living epidermal cells which divide forming new cells. After two weeks, they die, move upward becoming part of the Upper Epidermis surface layer. Function: protects, cushions, carries away bacteria, produces melanin. Melanin – skin (color) pigment which protects against burning

4. SKIN NOTES

5. DERMIS: located below the epidermis and above the fat layer ** contains the nerves, blood vessels, sweat and oil glands, hair follicle. Sweat glands- produce perspiration (temperature regulation) Oil glands – waterproof hair and keeps skin moist Hair follicle – site of hair growth Below Dermis: Fat Layer, Muscle, Bone

6. SKIN NOTES Skin Health: diet keep clean and dry limit sun exposure See dermotologist every year to check skin for precancerous growths Skin Cancer: over exposure to sunlight can damage skin cells where cells divide uncontrollably (basal cell carcinoma, squamous cell carcinoma, malignant melanoma). Too much Sun: skin leathery and wrinkled

7. Dangerous Melonoma Note: black, dark brown color; irregular outline

8. Basal Cell Carcinoma pink, raised, blister; irregular outline

9. Squamous Cell Carcinoma pink, raised, blister with central, depressed cavity; irregular outline

10. Skin Cancers