The Integumentary System

The Integumentary System Chapter 6

Layers of Skin - Epidermis• Epidermis is the

outermost main layer of the skin

• The epidermis has 5 sub layerso stratum corneum

stratified squamous epithelium

20 layers of dead cells- very flat

mostly keratin (protein) normally the body sheds

thousands per day

outside

inside

Layers of Skin - Epidermis• The epidermis has

5 sub layerso stratum lucidum

four layers at the top on palmar and plantar surface only

o stratum granulosum essentially dead cells lysosomes have

destroyed almost all organelles

outside

inside

Layers of Skin – Dermis

• Middle main layer beneath the epidermis

• Composed mostly of connective tissue

• Location rich in collagen, a structural protein

Layers of Skin – Dermis• Components of the dermis

o blood vesselso nerves

• hair follicles• glands

Layers of Skin – Dermis

• Dermal papillaeo finger-like projections of

the dermis into the epidermis

o rich in blood supply = blood and nutrients

o zone of temperature regulation

Layers of Skin – Dermis• Dermal papillae

o Fingerprints - dermal friction ridges are a result of patterns of dermal papillae (epidermal ridges)

Layers of Skin – Subcutaneous fascia (layer)• Adipose is stored

here - energy storage in locations called subcutaneous fat pads

• The loose arrangement allows for skin movement

• Adipose is needed for insulation from heat loss

Layers of Skin – Subcutaneous fascia (layer)• Adipose is needed for insulation from heat

loss