THE SKIN OR INTEGUMENTARY SYSTEM

Remember the outer portion of the skin is an example of what type of

tissue?

Epithelia Tissue

FUNCTIONS OF THE SKIN

• PROTECTION• THERMOREGULATION

• CUTANEOUS SENSATION• PRODUCTION OF VITAMIN D

• BLOOD RESERVOIR• EXCRETION

LAYERS OF THE SKIN

EPIDERMIS

DERMIS

HYPODERMIS

EPIDERMIS

• THICK• KERATINIZED

• STRATIFIED SQUAMOUS EPITHELIUM• 4-5 SUBLAYERS

LAYERS OF THE EPIDERMIS

• STRATUM BASALE• STRATUM SPINOSUM

• STRATUM GRANULOSUM• STRATUM LUCIDUM• STRATUM CORNEUM

STRATUM BASALE

• THE DEEPEST EPIDERMAL LAYER• A SINGLE ROW OF LIVING CELLS

• RAPID CELL DIVISION• 10-25% OF THESE CELLS ARE

MELANOCYTES

STRATUM BASALE

STRATUM SPINOSUM

• SEVERAL LAYERS OF LIVING CELLS

• CELL DIVISION IS SLOWER THAN BASALE

STRATUM SPINOSUM

STRATUM GRANULOSUM

• THIN, LIVING LAYER OF CELLS

• KERATINOCYTES WATERPROOF IN THIS LAYER

STRATUM GRANULOSUM

STRATUM LUCIDUM

• DEAD CELLS

• LOCATED ONLY IN THICK SKIN (PALMS OF HANDS & SOLES OF FEET)

STRATUM LUCIDUM

STRATUM CORNEUM

• DEAD CELLS

• SERVES TO PROTECT

STRATUM CORNEUM

THE DERMIS

HAIR FOLLICLES, OIL & SWEAT GLANDS ARE FOUND HERE

EPIDERMIS

DERMIS

HAIR & ITS FUNCTIONS

• WARMTH; IT PREVENTS HEAT LOSS

• DETECT INSECTS ON THE SKIN

• PROTECTION

• FILTER PARTICLES

FACTS ABOUT HAIR

• ABOUT 100,000 IN THE SCALP

• ABOUT 30, 000 IN A MAN’S BEARD

• RATE OF HAIR GROWTH AVERAGES 2 mm/WEEK

• HAIR LOSS AVERAGES 90 HAIRS/DAY

HAIR LOSS• ALOPECIA: HAIR THINNING AND BALDNESS

CAUSES OF HAIR LOSS

• HIGH FEVER• SURGERY

• SEVERE EMOTIONAL TRAUMA• CERTAIN DRUGS

• EXCESSIVE VITAMIN A• CHEMOTHERAPY DRUGS

• RADIATION• GENETICS

MOST IMPORTANT

• POOR NUTRITION (ESPECIALLY LACK OF ENOUGH PROTEIN)

• HORMONAL IMBALANCES