Skin AppendagesSkin Appendages

►Cutaneous glands Sebaceous glands Sweat glands

►Hair►Hair follicles►Nails

These appendages come from the epidermis and help maintain the body’s homeostasis.

Appendages Appendages of the Skinof the Skin

►Sebaceous glands Produces oil

► Lubricant for skin which keeps skin soft and moist

► Prevents brittle hair► Kills bacteria (slightly acidic)

Most have ducts that empty into hair follicles; others open directly onto skin surface

Glands are activated at puberty and this is what causes teenage acne

Sebaceous GlandsSebaceous Glands

Facial BlemishesFacial Blemishes►WhiteheadWhitehead – –

sebaceous gland is sebaceous gland is blocked usually from blocked usually from the oily substance the oily substance made by the gland.made by the gland.

► BlackheadBlackhead – when – when whitehead dries, it whitehead dries, it darkens forming darkens forming blackheadblackhead

► AcneAcne – an active – an active infection of the infection of the sebaceous glands sebaceous glands caused by bacteriacaused by bacteria

►Sweat glands Produce sweat widely Produce sweat widely

distributed in skin distributed in skin (2.5 million per person)(2.5 million per person)

helps cool the bodyhelps cool the body Two typesTwo types

► Eccrine Opens up to skin through a Opens up to skin through a

duct (pore) on skin surfaceduct (pore) on skin surface Most numerous on the bodyMost numerous on the body

► Apocrine Ducts empty into hair folliclesDucts empty into hair follicles Found mostly in armpits and genital areasFound mostly in armpits and genital areas Precise function is unknown but are they Precise function is unknown but are they

are activated during pain, stress and are activated during pain, stress and during sexual foreplay.during sexual foreplay.

Sweat’s Sweat’s FunctionFunction

►CompositionComposition Mostly waterMostly water Salts and excess vitamin CSalts and excess vitamin C Some metabolic waste (urea and uric acid)Some metabolic waste (urea and uric acid) Fatty acids and proteins (apocrine only)Fatty acids and proteins (apocrine only)

►FunctionFunction Helps rid body of excess heatHelps rid body of excess heat Excretes waste productsExcretes waste products Acidic nature inhibits bacteria growthAcidic nature inhibits bacteria growth

►Odor is from associated bacteriaOdor is from associated bacteria

Appendages of the Appendages of the SkinSkin

►HairHair Produced by hair follicles Produced by hair follicles

which are made of hard which are made of hard keratin made by keratin made by keratinocyteskeratinocytes

MelanocytesMelanocytes provide provide pigment for hair colorpigment for hair color

Structure of Hair FollicleStructure of Hair Follicle

Keratin produced by cells that surround papilla (hair bulb)

A Muscle for each HairA Muscle for each Hair Arrector pili muscle

►Smooth muscle►Pulls hairs upright when cold or

frightened When contracted, bulging of muscle

creates goosebump – releases heat for warmth

NailsNails►NailsNails Heavily Heavily keratinizedkeratinized Keratinocytes Keratinocytes in the Stratum basalein the Stratum basale

extends beneath the nail bed – extends beneath the nail bed – Responsible for growthResponsible for growth

Lack of pigment makes them colorlessLack of pigment makes them colorless

Severity of BurnsSeverity of Burns

►First-degree burnsFirst-degree burns Only epidermis is damagedOnly epidermis is damaged Skin is red and swollenSkin is red and swollen

►Second-degree burnsSecond-degree burns Epidermis and upper Epidermis and upper

dermis are damageddermis are damaged Skin is red with blistersSkin is red with blisters

►Third-degree burnsThird-degree burns (worst)(worst) Destroys entire skin layerDestroys entire skin layer Burn is gray-white or blackBurn is gray-white or black