Module 7: Skin Structure, Growth and

Nutrition

Anatomy of the Skin

• Dermatology - The medical branch of science that deals with the study of skin and its nature, structure, functions, disease, and treatment

• Dermatologist – is a physician engaged in the science of treating the skin, its structures, functions and diseases.

• Esthetician – is a specialist in the cleansing, preservation of health and beautification of the skin and body.

Cosmetologists are not allowed:

• To diagnose• Prescribe• Provide treatments for :

• Abnormal conditions• Illnesses• Diseases

• Largest Organ of the body– 3,000 square inches– 6 - 9 lbs.

• Slightly moist• Soft• Flexible• Texture – ideally smooth and fine

grained• Slightly acidic

• Immune responses react quickly to touch

• Appendages– Hair– Nails– Sebaceous glands– Sudoriferous glands

Skin• Thinnest - eyelids• Thickest – soles of feet and palms of

hands• Callus – continued pressure can

cause skin to thicken• Scalp – larger, deeper follicles to

accommodate longer hair• Did you know boxes – page 157

Two Main Divisions

• Epidermis – Outer most layer– Cuticle– Scarf skin– Thinnest layer– Protective covering for body– Contains no blood vessels– Has many nerve endings

Layers of Epidermis

• Stratum Corneum – outer layer – – scale-like cells continuously shed and replaced

by cells coming to the surface from underneath

– Keratin – protein– Cells combine with a thin layer of lipids

(fats/oils) to make a protective water-proof layer

• Stratum Lucidum- clear, transparent layer – small cells through which light can pass

• Stratum Granulosum – cells that look like distinct granules– Cells die, pushed to surface, replace cells

being shed from stratum corneum

• Stratum Spinosum– Spiny layer– Beginning of process that causes skin cells to

shed

• Stratum Germinativum – basal or Malpighian layer– Deepest layer of Epidermis– Several layers of different-shaped cells– Live layer - Responsible for the growth of the

Epidermis– Contains a dark skin pigment (melanin)– Melanocytes – produce melanin which

determines skin color

• Did you know box – page 158

Dermis

• Underlying or innermost layer– Derma, corium, cutis or true skin

• 25 times thicker than Epidermis• Within its structure

– Blood vessels - Nerves– Lymph vessels - Sweat Glands– Oil glands - Hair follicles– Arrector pili muscles – goose bumps– Papillae – small coned shaped projections of

elastic tissue that point upward into the epidermis

Two layers of Dermis• Papillary Layer

– Outer layer, lies directly beneath the epidermis

– Papillae located here– Tactile corpuscles – structures with nerve

endings that are sensitive to touch and pressure

– Melanin– Joins the Epidermal – dermal Junction

• Reticular Layer– Deeper layer that supplies the skin with oxygen

and nutrients– Fat cells– Blood vessels– Lymph vessels– Oil glands– Sweat glands– Hair follicles– Arrector pili muscles

• Did you Know – page 159

Subcutaneous Layer

• Fatty layer found below the dermis• Tissue called adipose or subcutis• Varies in thickness according to

– Age– Sex– General health

• Gives smoothness and contour to the body• Contains fat for use for energy• Acts as a protective cushion for the outer

skin

How the Skin is Nourished

• Blood and lymph supply nourishment to the skin

• Contribute essential materials for:– Growth– Nourishment– Repair of skin, hair and nails

• Lymph– Clear fluid – Colorless corpuscles– Bathe skin cells– Remove toxins and cellular waste– Immune functions help protect body

and skin

Nerves of the Skin• Motor Nerves –

– attached to the arrector pili muscles– Carry impulses from brain to muscles

• Sensory Nerves –– React to cold, touch, pressure, pain– Receptors send messages to the brain

• Secretory Nerves – Distributes to oil and sweat glands– Autonomic Nervous System– Regulate the excretion of perspiration from the

sweat glands– Control the flow of sebum to the surface of the

skin

• Sense of Touch– Nerve endings register basic sensations – touch,

pain, heat, cold, pressure– Nerve endings most abundant in the fingertips

Skin Color

• Melanin – tiny grains of coloring matter• Distinctive color of skin is a hereditary

trait• Varies among nationalities and races• Pheomelanin – red – yellow• Eumelanin – dark brown - black• Melanin protects sensitive cells against

strong light rays

Strength and Flexibility of the Skin

• Skin gets its strength, form, flexibility from two specific structures of flexible protein fibers

• Make up 70% of the dermis• Collagen –

– Fibrous protein that gives skin form and strength

– Helps give structural support by holding together all the structures found in this layer

– Allow skin to stretch and contract– If fiber become weakened – lose its tone and

suppleness

• Elastin – interwoven with collagen– Protein base similar to collagen that forms

elastic tissue– Gives skin its flexibility and elasticity– Helps skin regain its shape

• Both fiber important to the overall health and appearance of skin

• As we age, fibers naturally weaken, causing a kind of wrinkling and sagging

• Most signs of aging are cause by sun exposure over a lifetime

• Did You Know? pp.161 & 162

Glands of the Skin

• Sudoriferous Glands– Sweat glands– Excrete perspiration– Detoxify body by excreting excess salt &

unwanted chemicals– Fundus – secretary coiled base– Tube-like duct that ends on the skin surface to

form sweat pore– Most numerous on palms of hands and soles of

feet

– Regulates body temperature– Eliminates waste– Controlled by the nervous system– 1 – 2 pints excreted daily

• Did You Know – pp. 163• Sebaceous Glands

– Oil glands– Connected to the hair follicles– Little sacs with ducts that open into the

follicles– Secrete sebum (oil)– Lubricates the skin– Preserves softness of the hair– On all parts of the body EXCEPT soles of feet

and palms of hands

• Comedo – a pore impaction – sebum hardens and the duct becomes clogged– Blackhead – a hair follicle filled with

keratin and sebum

Acne• Acne Vulgaris

– Chronic inflammation of the sebaceous glands from retained secretions and bacteria – Propionbacterium acnes (p. acnes) – technical term for acne bacteria

• Pimple – a small elevation on the skin that contains no fluid but may develop pus

• Pustule – raised, inflamed papule with a white or yellow center containing pus in the top of the lesion (head of pimple)

Functions of the Skin

• Protection: Protects the body from injury and bacterial infection

• Sensation: By stimulating sensory nerve endings• Heat Regulation: Skin protects the body from the

environment• Excretion: Perspiration from the sweat glands is

excreted through the skin• Secretion: Sebum excreted. Lubricates the skin

and keeps it soft and pliable • Absorption: Female hormones can enter the body

through the skin, and influence it to a minor degree, fatty materials are absorbed largely through the air follicles and sebaceous gland openings

Nutrition & Maintaining Skin Health

• “You are what you eat”• Proper dietary choices

– Regulate hydration– Oil production– Overall function of the cells

• Can be caused by un healthful diet or improper hydration– Skin disorders– Fatigue– Stress– Depression– Some diseases

Essential Nutrients

• Eat foods from 3 basic groups– Fats– Carbohydrates– proteins

• Must also have:– Vitamins– Minerals– Water

USDA and USDH&HS

• FYI page 165• Grains• Milk• Vegetables• Fruits• Meat, poultry, fish, beans

– Page 166 – list

• Dietary Guidelines : Dietary Guidance : Food and Nutrition Information Center

• Physical Health and Nutrition - The Office of Adolescent Health

• Read food labels• Nutrition facts about serving size• Number of servings per container• Calories• Quantities of nutrients per serving

Vitamins and Dietary Supplements

• Aide in: – Healing– Softening– Fighting diseases of the skin

• Taking vitamins internally (pill form)best way

Vitamin A

• Supports overall health of skin– Health– Function– Repair of skin cells

• Antioxidant – prevents certain cancers (skin)

• Improve skin’s elasticity and thickness

• Topical form– Prescription form– Retinoic acid– Retin-A®

• Treatment of acne

Vitamin C

• Ascorbic acid – topical form• Proper repair of skin and various

tissues• Aides in and speeds up healing

processes of the body• Vitally important in fighting :

– Aging process– Promotes production of collagen– Keeping skin healthy and firm

Vitamin D

• Promotes healthy and rapid healing of skin

• Best source is sunlight• Fortified milk/orange juice• Supports bone development &

maintenance

Vitamin E

• With vitamin A – helps fight against and protect skin against harmful effects of sun’s rays

• Heals damage to skin’s tissues when used internally & externally

• Topical – Heal structural damage– Burns– Stretch marks

• Strive to improve diet rather than take vitamins /mineral supplements

• Clients might ask you about nutrition

• Ask about hair, skin,. Nail problems

Water and the Skin

• No person can live without it• The body and skin both rely heavily on

the benefits of water• Composes 50 – 70 % of the body’s

weight• Sustains the health of the cells, aids in

the elimination of toxins and waste, regulates the body’s temperature and aids in proper digestion

Amount of water needed per person

• Take your body weight and divide by 16• Resulting number approximates how

many 8 ounces glasses of water you should drink every day

• If intense physical activity is performed daily – add 2 extra glasses of water to your final number

• Did You Know? (pp. 167)• FYI – (pp. 166)