Accessory Organs of the Skin

Hair Characteristics Location: Almost everywhere (soles, palms,

lips ect.) Structure:

Hair follicle- organs producing hair, epidermal strata

Hair papilla- follicle base, CT, capillaries & nerves Hair matrix- ET stem cells Hair bulb- swelling of follicle, growth Hair root-anchors hair into skin Hair shaft- visible portion, dead, keratinized cells

Cuticle-outer Medulla-middle Cortex -inner

Hair Characteristics Cont.Growth: Hair is produced in cycles-growth and rest phases

Typically grows 2-6 years (approximately 0.3 mm a day)

Typically rests 2-3 months When new hair begins growing the older hair is

pushed outward to drop off- we lose about 100 scalp hairs a day.

Color: Genes determine hair color by directing the type

and amount of pigment the epidermal melanocytes produce.

Texture: Shape of the hair follicle will determine what

texture the hair shaft is.

Hair Function

Protection Cushion Insulation

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Nails Location/Function: protective coverings on

the ends of finger and toes Structure:

Free edge-white portion of the nail that grows out from the finger or toe

Nail body (plate)-dead, keratinized epithelial cells

Nail bed-skin beneath nail plate Nail root- growth site, deep to cuticle Cuticle- extends over the exposed nail,

protection Lanula- pale crescent area

Nail Appearance Health factors can be seen in nail

appearance. Bluish nails-reflect circulation problems White nail bed or depressions-anemia, zinc or

calcium definceny Pigmented spot under nail-melanoma Horizontal furrows-Malnutrition/illness Extreme curvature-lung, heart or liver

disorders Red streaks-rheumatoid arthritis, ulcers or

hypertension Yellow-numerous disorders from AIDS-

Bronchitis

Skin Glands- Exocrine glands1. Sebaceous Glands- or oil glands, contain groups of specialized epithelial cells that are usually associated with hair follicles.

Holocrine glands Cells produce globules of a fatty

substance that accumulate, swelling and bursting the cells-the result is known as sebum.

Sebum is secreted into the hair follicles through short ducts to keep hair and skin soft, pliable and waterproof.

Acne results from excess sebum secretion

Found all throughout the skin except palms and soles.

Skin Glands Cont. 2. Sweat Glands-or sudoriferous glands are

widespread in the skin. Originates as ball-shaped coil in the deeper dermis or

subcutaneous layer. Eccrine (merocrine) Glands- most numerous sweat

gland (2-5 million) that respond to body temperature by environmental heat or physical exercise High amounts in palms/soles, forehead, neck and back Discharge secretions directly onto the skins surface

Apocrine glands- secretions develop a scent as they are metabolized by skin bacteria. Become active at puberty Active when a person is upset, frightened, in pain or

during sexual arousal Common in the axillary region, groin, and around the

nipples. Open into hair follicles