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