Milady’s Standard Cosmetology

HISTOLOGY OF THE SKIN

17Copyright © 2004 by Delmar Learning, a division of Thomson Learning,Inc.

17

ANATOMY OF THE SKIN

Dermatology—deals with the study of skin and its nature, structure, functions, diseases, and treatment

Dermatologist—a physician engaged in dermatology

Esthetician—a specialist in the cleansing, preservation of health, and beautification of the skin and body

17

HISTOLOGY OF THE SKIN

Healthy skin is slightly moist. is soft and flexible. has smooth and

fine-grained texture.

possesses slightly acid reaction.

Appendages of the skin: Hair Nails Sweat and oil

glands

The skin is the largest and one of the most important organs of the body.

17

HISTOLOGY OF THE SKIN

Epidermis Outermost layer, commonly

called cuticle or scarf skin thinnest layer of skin; forms protective covering; contains no blood vessels

Dermis Inner layer of skin, called

derma, corium, or true skin; about 25 times thicker than the epidermis and is highly sensitive Figure 17-1

17

EPIDERMIS

Stratum corneum—horny outer layer. Its scale-like cells are constantly shed and replaced. Cells contain protein keratin and combine with thin covering of oil to make the skin almost waterproof.

Stratum lucidum—clear, transparent layer consisting of small cells through which light can pass.

17

EPIDERMIS

Stratum granulosum—granular layer in which cells look like granules. Cells are almost dead and are pushed to the skin’s surface to replace those that are shed from the stratum corneum.

Stratum germinativum—formerly known as

stratum mucosum; deepest layer, responsible for growth of the epidermis; contains pigment called melanin, also found in hair. Pigment in this layer protects skin cells from ultraviolet rays by cells called melanocytes that produce melanin.

17

DERMIS

Papillary layer—lies directly beneath the epidermis; contains small cone-shaped projections (called papillae) of elastic tissue that point upward to the epidermis. Some papillae contain looped capillaries. Others contain nerve fiber endings for the sense of touch called tactile corpuscles; contains melanin.

Reticular layer—contains fat cells, blood and lymph vessels, sweat and oil glands, hair follicles, and arrector pili muscles. Supplies skin with oxygen and nutrients.

17

HOW SKIN IS NOURISHED

Blood and lymph circulate through skin and contribute essential material for growth, nourishment, and repair of skin, hair, and nails.

17

NERVES OF THE SKIN

Motor nerve fibers—distributed to arrector pili muscles

Sensory nerve fibers—react to heat, cold, touch, pressure, and pain; send messages to the brain; found in papillary layer; abundant in fingertips

Secretory nerve fibers—distributed to sweat and oil glands; regulate excretion of perspiration and control flow of sebum to the surface of the skin

17

SKIN COLOR

Skin color depends on blood supply.

Melanin, the pigment deposited inside the stratum germinativum and the papillary layer in the dermis.

Hereditary traits vary among races and nationalities.

Dark skin contains more melanin; light skin contains less. Figure 17-3

17

STRENGTH and FLEXIBILITY

Collagen Fibrous protein that gives skin form and

strength

Elastin Protein base that forms elastic tissue

17

GLANDS OF THE SKIN

SUDORIFEROUS GLANDS Also called sweat glands Have coiled base and tube-like duct to skin

surface Are numerous on palms, soles, forehead, and

armpits Regulate body temperature Help eliminate waste Eliminate 1 to 2 pints of salty liquid daily;

controlled by the nervous system

17

GLANDS OF THE SKIN

SEBACEOUS GLANDS These are oil glands. They are little sacs that open to skin’s

surface. They secrete sebum. They are found everywhere except on

palms and soles. Sebum flows from ducts to follicles. If duct is clogged, oil will harden and a

blackhead will form.

17

FUNCTIONS OF THE SKIN

PROTECTION - Injury - Bacteria

SENSATION - Heat - Touch - Pressure - Pain

HEAT REGULATION - Protects the body from environment

EXCRETION - Perspiration takes salt and other chemicals with it

SECRETION - Oil lubricates skin - Emotional stress will increase the flow

ABSORPTION - Limited but will absorb - Female hormones - Creams

17

FUNCTIONS OF THE SKIN

SENSORY NERVE ENDINGS OF THE SKIN

Figure 17-5

17

AGING OF THE SKIN

The sun The environment Health habits General lifestyle

Cigarette smoking has been linked to premature aging and wrinkling.

17

SUN AND ITS EFFECTS

SUN EFFECT 80% to 85% of aging is caused by the

sun’s rays. UVA rays

Aging rays 90% of sun’s ultraviolet rays

UVB rays Burning rays Effects on melanocytes, cells that produce

melanin

17

SUN AND ITS EFFECTS

PRECAUTIONS Wear protective lotion Avoid sun exposure during peak hours Apply sunscreen liberally after

swimming Avoid exposing children under six

months Wear hat and protective clothing

outdoors

17

SKIN AGING AND THE ENVIRONMENT

ENVIRONMENTAL FACTORS Pollutants from factories Emissions from automobiles Secondhand cigarette smoke

DEFENSE Good daily skin care routine Washing and exfoliating Using moisturizers, protective lotions,

foundation

17

DISORDERS OF THE SKIN

Primary lesions (LEE-zhuns)

Bulla Cyst Macule Papule Pustule Tubercle Tumor Vesicle Wheal

Figure 17-6

17

DISORDERS OF THE SKIN

Secondary lesions Crust Excoriation Fissure Keloid Scale Erosion Ulcer Figure 17-10

17

DISORDERS OF THE SKIN

SEBACEOUS (OIL) GLANDS

Comedone—blackhead; worm-like mass of hardened sebum in hair follicle

Milia—whiteheads caused by accumulation of sebaceous matter beneath skin

Figure 17 - 12

17

DISORDERS OF THE SKIN

SEBACEOUS (OIL) GLANDS

Acne—skin disorder characterized by chronic inflammation of the sebaceous glands from retained secretions

Seborrhea—excessive secretion of sebaceousglandsFigure 17-14

17

DISORDERS OF THE SKIN

SEBACEOUS (OIL) GLANDS

Asteatosis—excessive dryness; scaly skin; partial deficiency of sebum

Rosacea—chronic congestion appearing primarily on the cheeks and nose

Steatoma—tumor in the subcutanous tissue filled with sebum ranging in size from a pea to an orange

Figure 17-15

17

DISORDERS OF THE SKIN

SUDORIFEROUS (SWEAT) GLANDS

Anhidrosis (an-hih-DROH-sis)—lack of perspiration, often a result of fever

Bromhidrosis (broh-mih-DROH-sis)—foul smelling perspiration

17

DISORDERS OF THE SKIN

Hyperhidrosis (hy-per-hy-DROH-sis)—excessive perspiration

Miliaria rubra—prickly heat; an acute disorder characterized by eruption of small red vesicles resulting in burning and itching; caused by excessive heat

17

DISORDERS OF THE SKIN

SKIN INFLAMMATIONS

Dermatitis—inflammatory condition of skin with lesions

Eczema (EG- zuh-muh)—skin inflammation of acute or chronic nature, presenting many forms of dry or moist lesions; accompanied by itching or burning Figure 17-16

17

DISORDERS OF THE SKIN

Herpes simplex—recurring virus infection, commonly called fever blisters

Psoriasis (suh-RY-uh-sis)—common, chronic, inflammatory skin disease found on scalp, elbows, knees, and chest Figure 17 -18

17

DISORDERS OF THE SKINOCCUPATIONAL DISORDERS Abnormal conditions can result from contact with

chemicals or tints.

Allergies can be developed to ingredients in cosmetics, antiseptics, perm solutions, and aniline derivative tints.

These can cause dermatitis venenata–eruptive skin infections.

To prevent, use rubber gloves and protective creams.

17

DISORDERS OF THE SKIN

PIGMENTATIONS OF THE SKIN Lentigines—freckles; small yellow- to brown-

colored spots on parts exposed to sunlight and air

Leukoderma—abnormal white patches in the skin due to congenital defective pigmentation

Nevus—birthmark Stains—abnormal brown skin patches having a

circular or irregular shape; occur during aging, after certain diseases, and after disappearance of moles, freckles, and liver spots

17

DISORDERS OF THE SKIN

PIGMENTATIONS OF THE SKIN

Tan—caused by exposure of the sun Chloasma—increased deposits of pigment in

the skin; found mainly on forehead, nose, and cheeks; also called moth patches or liver spots

Albinism—the absence of melanin pigment of the body, skin, hair, and eyes

Vitiligo—acquired condition of leukoderma affecting skin or hair

17

DISORDERS OF THE SKIN

HYPERTROPHIES OF THE SKIN

Keratoma—an acquired thickened patch of skin or epidermis due to pressure of friction on hands and feet. If it grows inward, it is called a corn.

Mole—small, brownish spot or blemish on the skin, believed to be inherited; range in color from pale tan to brown to bluish black. Some are small and flat; others are raised and darker. DO NOT REMOVE HAIR FROM MOLES.

17

DISORDERS OF THE SKIN

HYPERTROPHIES OF THE SKIN

Skin tag—small brown or flesh-colored outgrowth of the skin

Verruca (vuh-ROO-kuh) or wart—caused by a virus and is infectious; can spread from one location to another, particularly along a scratch in the skin

17

DISORDERS OF THE SKIN

SKIN CANCER

Basal cell carcinoma (kar-sin-OH-muh)

Figure 17-23

17

DISORDERS OF THE SKIN

SKIN CANCER Squamous

(SKWAY-mus) cell carcinoma

Malignant melanoma (mel-uh-NOH-muh)

Figure 17-25

17

MAINTAINING HEALTH OF THE SKIN

VITAMINS and SUPPLEMENTSVitamin A Aids in health, function, and repair of skin cells Is an antioxidant that can help prevent skin

cancer Can improve skin’s elasticity Known as retinoic acid or Retin-A as a

prescription creamVitamin C Needed for proper repair of skin and tissues Speeds up healing process Promotes collagen production

17

MAINTAINING HEALTH OF THE SKINVITAMINS and SUPPLEMENTS Vitamin D

Promotes healthy skin Promotes rapid healing of the skin

Vitamin E Helps to heal damage to skin’s tissues Topically, helps heal structural damage to

skin

17

MAINTAINING HEALTH OF THE SKINVITAMINS and SUPPLEMENTS

Water Composes 50% to 70% of body’s weight Sustains health of the cells Aids in elimination of toxins and waste Helps regulate body’s temperature Average person’s needs—8 to 10 (8 ounces) glasses of water a dayDehydration Slows metabolism 75% of Americans chronically dehydrated

17

SKIN DISEASE DEFINITIONS

disease—any departure from normal state of health

acute disease—one with symptoms of a more or less violent character such as fever

chronic disease—one of long duration, mild but recurring

infectious disease—due to bacterial or viral germs resulting from contact with contaminated objects

contagious—communicable by contact

congenital—born with it

17

SKIN DISEASE DEFINITIONS

seasonal—influenced by weather

occupational—due to certain kinds of employment that involve coming in contact with chemicals and the like

parasitic disease—one caused by parasites (ringworm)

pathogenic disease—produced by disease-causing bacteria (staph or strep viruses)

systemic—due to under- or overfunctioning of internal glands; may be caused by a faulty diet

17

venereal disease—contagious, caused by contact with an infected person during sexual intercourse

epidemic—simultaneously attacks a large number of people living in a particular locality (flu, smallpox)

allergy—a sensitivity to normally harmless substances such as cosmetics, medicines, tints, and certain foods

inflammation—characterized by redness, pain, swelling, or heat

SKIN DISEASE DEFINITIONS

17

SUMMARY

The skin is the largest organ of the body and protects us from the environment.

It regulates body temperature and provides sensation.

Skin can be affected quite easily by most salon services.

It is important that you know what products can penetrate the skin and what effects they will have on your clients.

By learning to identify various diseases and disorders of the skin, you will be able to provide more effective and safe services for your clients.