Chapter # 3

Integumentary SystemBy: Precious Blanton

Introduction The integumentary system is the external

covering of the body, including skin, hair, nails and sweat glands. The integumentary system is responsible for excreting wastes and regulating temperature, and is the location of sensory receptors for pain, pressure and temperature. During this presentation I will list and describe the three layer of skin and their function. I hope you enjoy and I hope you will find helpful, informative on the integumentary system.

Tissues of the skin (there are three layer) . Dermis- largely connective tissue; manynerves and blood vessels; smooth muscle. Also, it

is 1-2mm thick,3mm thick on the soles and palms.

Did you know the male skin is thicker than females?

Subcutaneous layer- is the innermost layer, containing fatty tissue.

epidermis- straitified squamous epitheliumbasement membrane.

In those parts of the skin which we perceive as "hairy" we find terminal hairs. The free part of each hair is called the shaft.

The root of each hair is anchored in a tubular invagination of the epidermis, the hair follicle, which extends down into the dermis and, usually, a short distance into the hypodermis.

The hair that you groom daily is actually dead keratinized cells.

Each hair follicle has an associated bundle of smooth muscle, the arrector pili muscle. This muscle inserts with one end to the papillary layer of the dermis and with the other end to the dermal sheath of the hair follicle. This makes your hair stand up on its end.

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Nails◦Plates of stratified squamous

epithelial cells with hard keratin◦Protect distal ends of phalanges◦Cells are keratinized in the nail root◦Nail growth occurs in the lunula◦Cuticle is a fold of stratum corneum

on the proximal end of nail

Two types of exocrine glands

Sebaceous- sebum (oil, wax)associated with hair follicleshelps maintain pliability of skin

Sweat glandsapocrine (armpits, groin)

merocrine (eccrine)- widely distributedimportant for maintaining body temperature

Aging and the integumentary system

Declines in:Cell division in stratum basaleMelanocyte productionGlandular activityHair follicle functionElastic fiber function in dermisBlood supply to skinRate of repair

Problems of skin

Lesionsinfections (bacterial, viral, fungal,parasitic)inflammatory reactions

allergensHyperkeratinization

Tumorsbasal cell (stratum basale)squamous cellmelanoma

Traumaabrasions, incisions, lacerations

Repairinflammationscab formationfibroblast activity (scar formation)

Burns- severity depends on depth of damage

Rashes- so many causes!

Conclusion The integumentary system is the organ

system that protects the body from damage, comprising the skin and its appendages(including hair, scales, and nails). I believe the integumentary system has a variety of functions; it may serve to waterproof, cushion and protect the deeper tissues, excrete wastes, regulate temperature and is the attachment site for sensory receptors to detect pain, sensation, pressure and temperature.Also, In humans the integumentary system additionally provides vitamin D synthesis.