SKIN FACTS :• GROWS FASTER THAN ANY OTHER ORGAN.• APPROX. 19,000,000 SKINS CELLS ON EVERY SQ. INCH OF YOUR BODY• ADULTS HAVE APPROX. 8 LBS & 22 SQ. FEET • HUMANS SHED ABOUT 600,000 PARTICLES

OF SKIN EVERY HOUR- 1.5 LBS. A YEAR• EACH SQUARE INCH OF SKIN CONSISTS OF

20 FT OF BLOOD VESSELS

DUST MITE

MORE SKIN FACTS:

• THE EPIDERMIS RENEWS ITSELF COMPLETELY EVERY

2 MONTHS.• NERVE CELLS IN SKIN MAKE IT

SENSTIVE TO TOUCH, PRESSURE & TEMPERATURE

SKIN: 2 MAIN LAYERS: EPIDERMIS & DERMIS

TOP LAYER OF SKIN: EPIDERMIS• MADE OF EPITHELIAL TISSUE• ARRANGED IN FLAT SHEETS• PREVENTS DAMAGE TO THE CELLS

THAT LIE BENEATH IT• UPPERMOST LAYERS MADE OF DEAD CELLS• THE DEEPER LEVELS CONTAIN SKIN PIGMENT- MELANIN

THE 2ND LAYER : THE DERMIS

•COMPOSED MAINLY OF CONNECTIVE TISSUE

•CONTAINS NERVES, MUSCLES,

BLOOD VESSELS, HAIR FOLLICLES & GLANDS

SKIN & HOMEOSTASIS

•PRIMARY FUNCTION IS TO ACT AS A PHYSICAL

BARRIER BETWEEN THE ORGANISM & ITS EXTERNAL

ENVIRONMENT

SKIN : PROTECTS FROM H2O LOSS

• THE PRESENCE OF CELLS CALLED

KERATINOCYTES IN THE EPIDERMIS HELPS PREVENT WATER LOSS - DEHYDRATION

DEHYDRATED SKIN

SKIN : HELPS MAINTAIN BODY TEMPERATURE

• THE DERMIS WITH ITS GREAT BLOOD SUPPLY, PLAYS A PART

IN MAINTAINING THE BODY’S TEMPERATURE BY CONSTRICTION

& DIALATION OF THE BLOOD VESSELS

SKIN : HELPS MAINTAIN BODY TEMPERATURE – SWEAT GLANDS

• THE EVAPORATION OF SWEAT FROM FROM THE SKIN CAUSES

THE BODY TO COOL.

SKIN: PROTECTS US FROM DISEASE

•THE TOUGH EPIDERMIS WITH

ITS ACIDIC ENVIRONMENT MAKES IT INHOSPITABLE TO MICROORGANISMS.

SKIN FUNGUS

SKIN : GIVES US SOME PROTECTION FROM UV RADIATION

• THE LOWER EPIDERMIS PRODUCES A PIGMENT CALLED MELANIN – WHICH IS REGULATED BY GENETICS &

EXPOSURE TO THE SUN. THE DARKER THE MELANIN THE LESS LIKELY YOU ARE TO BURN.

SEVERE SUNBURN

MELANOCYTES – SKIN PIGMENT

ALBINISM

SKIN PIGMENTS

SKIN: SENSITIVITY & COMMUNICATION• FINGERS MOST SENSITIVE TO STIMULI - THE BACK THE LEAST.• CAN COMMUNICATE THE STATE OF HEALTH BY COLOR CHANGE: EX.

FLUSHED• CAN CONVEY EMOTION – BLUSHING• HELP US TO INTERACT WITH OUR ENVIRONMENT

SKIN RESPONSE : GOOSE BUMPS