ANATOMY & PHYSIOLOGYINTEGUMENTARY SYSTEM

PART 2

Appendages of the Skin

Skin Appendages

Glandsall arise from stratum basale then

extend into dermis & subcutaneous layers

all exocrine glands Release product thru a duct onto surface of skin

Hair & Hair FolliclesNails

Cutaneous Glands

1. Sebaceous (Oil) Glands2. Sweat Glands

Sebaceous Glands

All over body except soles & palmsmost ducts empty onto hair follicle,

rest empty directly onto skin

Sebaceous Glands Secrete Sebum

Sebum:Oily substances + fragmented cellsBecome more active in puberty

(androgen effect)Function:

keeps skin soft & moist, prevent hair from becoming brittle kills bacteria

Sebaceous Gland

If duct becomes blocked whitehead forms

With time oxidizes blackhead formsIf becomes infected pimple

Seborrhea (Cradle Cap)

Seen in newborns & infantsDue to overactivity of sebaceous

glandsStarts as pink, raised lesions form

yellow to brown crust sloughs off as oily dandruff

Sudoriferous Glands

aka sweat glands1 body has > 2.5 million

2 Types:1. Eccrine glands2. Apocrine glands

Eccrine Sweat Glands

more of these than apocrine sweat glands

Product: Sweat

Sweat is made up of:WaterNaClVitamin CUrea & uric acidLactic acid

Eccrine Glands

Important part of thermoregulation function of skin

Nerve endings send action potential when body temperature or external temperrature > normal

When water in sweat evaporates body cools due to high heat of vaporization of water

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Apocrine Sweat Glands

In axilla and genital areasUsually larger than eccrine glandsDucts empty into hair folliclesBegin to function during pubertyIf infectedwith bacteria odorProduct:

Fatty acids Proteins + what is in eccrine sweat

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Hair Follicles

Scattered all over body except palms & soles

Functions:Protection Insulation

Hair Follicles

Nails

Homeostatic Imbalances

Skin is largest organ so see many skin conditions

Most common ailments fall into categories1. Infections2. Allergies3. Skin cancer4. Burns

INTEGUMENTARY SYSTEMPART 3

Homeostatic Imbalances of the Skin

Bacterial Infections

Boils & Carbuncles Infected sebaceous glands (especially

neck)Staphylococcus areus

Impetigo

See blister-like pink lesions around nose, mouth yellow crusty

Elementary school ageExtremely contagious staph

Athlete’s Foot

Itchy, red, peelingUsually starts between toesTinea pedis

Cold Sores(Fever Blisters)

Herpes simplexRed, blisters, soreVirus remains dormant in cutaneous

nerveHerpes is Forever

Contact Dermatitis

Itching, redness, swellingSkin reacting to metal, chemical (in food,

poison ivy)

Psoriasis

Chronic conditionScaly, red to silvery scalesFrequently starts on elbow, knee , scalp:

can spreadTreatment: cortisone cream

Burns

Tissue damage & cell death caused by intense heat, cold, electricity, UV radiation, acids

Rule of Nines:

1st Degree Burns

Only epidermis is damagedHeals after 2-3days discomfortExample: sunburn

2nd Degree Burn

Epidermis & upper dermis damagedRed, blisters, painfulRegeneration possible With 1st degree burns :

Partial thickness burns

3rd degree burns

Full thickness burn: damage to all layers of skin

Not painful (nerve endings destroyed)Regeneration not possibleSkin grafting

Skin Cancer

Fastest rising cancer in young adults3 kinds:1. Basal Cell Carcinoma2. Squamous Cell Carcinoma3. Malignant Melanoma

4. Metastasis to Skin

Basal Cell

Starts in stratum basaleSlow, rare to metastasizeVery common in sun-exposed areas#1 cause:sun exposure

Squamous Cell Carcinoma

Stratum spinosumLess common, more likely to metastasizeSun exposed areas

Malignant Melanoma

5 % of skin cancer but the deadliestRisks

Family historyChanging moleHistory of severe sunburns, tanning

bed useTreatment: surgery, chemotherapy

Malignant Melanoma

ABCD Rule

A: asymmetry, pigmentation not uniformB: border irregularityC: colors vary in same spotD: diameter > end of pencil eraser

Tattoos

Needle injects ink into derrmisPigment can migrate, safety not well

establishedNeedle infections not uncommon

Hepatitis C liver cancerLASER to remove

Development of the Skin

Lanuga: soft , fine hairs that develop in 5th -6th month of pregnancy

Vernix caseosa: creamy, thick, white substance produced by sebaceous glands in 2nd half pregnancyKeeps skin soft, moist

Development of the Skin

Milia:small white spots frequently seen on newborn – 3rd week after birth

Accumulations in sebaceous glands

Skin Changes with Aging

Subcutaneous tissues decrease leading to:1. Intolerance to cold2. Skin drier due to decreased oil

production & less collagen fibers3. More likely to bruise 4. Decreased elasticity (baggy skin)