OBJ: Given video, notes, activity sheet SWBAT describe the structures and functions of the skin with 70% accuracy.

BRING IN TEXTBOOKDN: 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).

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

SKIN NOTESEPIDERMIS (OUTER LAYER):

No nerves, no blood vesselsUpper Epidermis (dead cell layer) – consists of dead cells which shed after two weeksLower 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

SKIN NOTES

SKIN NOTESDERMIS: 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 moistHair follicle – site of hair growth

Below Dermis: Fat Layer, Muscle, Bone

SKIN NOTESSkin 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

Dangerous MelonomaNote: black, dark brown color; irregular outline

Basal CellCarcinoma

pink, raised, blister; irregular outline

Squamous Cell Carcinomapink, raised, blister with central, depressed cavity; irregular outline

Skin Cancers