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General structure: composed of epidermis , dermis, separated by a basement membrane and a subcutaneous layer underneath

Has at least 8 functions!Integumentary System- L2Function #1: Protective barrier against

Loss of body fluidsInfectionDamage from physical injury Heat/UV lightPhysical stress

Function#2: Thermal regulation1. Sweat from sweat glands2. Controls blood supply to warm/cool body3. insulation: barrier against outside 4. Radiation of heat (#1 way to cool body) and evaporation also a close #2Function #3 Sensory receptors in skin react to1. changes in temp2. touch-pressure-painFunction #4: Excretion of Wastes1. Since it self-renews it can get rid of nitrogen, salt, ureaFunction #5 -#8: vitamin D production energy storage (fat) fingers and toes provide a gripping surfaceBlood reservoir. (skin has about 8-10% of one's blood.) First layer: EpidermisHas 5 layers of avascular stratified squamous tissue Has cells called keratinocytes and melanocytes Keratinocytes produce the protein keratin. It makes up skin surface, hair and nails Keratin helps waterproof and protect.

Second layer: Dermis (primarily connective tissue) with the following1. Has many nerves and blood vessels going through it.2. The cells of the dermis are primarily fibroblasts. 3. The intercellular material is largely collagen and elastin laid down in all directions by the fibroblasts.4. Adipose cells are also common

Third Layer: Subcutaneous Layer (hypodermis) - primarily connective tissue, adipocyte cells are more predominant. This layer contains blood vessels that supply the skin. Cells called: Melanocytes1. Melanocytes are in the basal layer of epidermis

A. Make black pigment called melaninB. this coloration protects against UV lightC. Native Americans and Asians have variations of melanin to have yellowish color to skinMelanocytes & TanningProlonged exposure to ultraviolet light stimulates melanocyte activity & melanin secretion in epidermis. This results in darker skin; the melanin protects the DNA of cells from UV damage by absorbing UV light. Too much exposure to UV light may overwhelm the protective function of melanin and result in sunburn.

FingerprintsSpecialized structure: Dermal papillaeUneven ridges formed during fetal developmentNO TWO sets are exactly alike!

Hair and follicle

1. Hair - made by epidermal keratin forming cells.a. Color = various levels of melanin and carotene. Gray is due to air spaces in the hair.b. Function?c. Growth is always from base. A new hair starts and pushes the old one out. Hair goes through growth-rest stages.

Sebacious gland: usually connected to hairA. glands that secrete sebum,B. Functions to keep skin and hair soft and waterproofC. Especially active during puberty. Can clog with dead cells/sebumpimple

Sebacious Gland, cont.D. Smooth muscle that lifts the hair is called the arrector pili.E. Nerve (sensory)F. Dermal Papillae: fingerprints. Projections extending into epidermis from dermis. Helps increase friction to help pick up things.Sweat glands: 3000/sq. inch1. # 1 Function- to cool the body2. Excretes wastes3. Regulated by nerves4. A modified form secretes more organic materials in arm pits/pubic area. Bacteria break it down and cause odor.

Nails:-protective covers on the ends of fingers and toes -undergo keratinization

1st degree burnEpidermis ONLY affectedRedness and burningEX: sunburn

Epidermal (1st degree) burn

2nd degree burnDamage to both the epidermis and dermisDamage not enough to PREVENT healing

Dermal (2nd degree) burn

Deep dermal (2nd degree) burn

3rd Degree burnENTIRE epidermis, dermis, and accessory organs destroyedTissue death

Sub-dermal (3rd degree) burn

Skin graft

Common disorders of the FeetAthlete's Foot(right down) Skin disorders of the feetsuch as Callus, Athlete's foot and Plantar Warts

Athlete's Foot(right down)

Tinea pedis- Athletes Foot

Acne

Contact dermatitis

Moles are harmless skin growths that may be flat or protruding. They vary in color from pink flesh tones to dark brown or black.

Pediculosis- lice

Decubitus ulcer (Bed sore)

Where do pressure ulcers form?Where bone causes the greatest force on the skin and tissue.For bedridden persons, most pressure ulcers form on the lower back below the waist (sacrum), the hip bone (trochanter), and heels.

40A pressure ulcer will form where bone causes the greatest force on the skin and underlying tissue.For bedridden persons, most pressure ulcers form on the lower back below the waist, hip bone & heels.

Diabetic Ulcer

Pathophysiology: diabetic foot ulcerationNeuropathySensoryLoss of protective sensationMotorAbnormal foot biomechanicsAutonomicReduced skin compliance and lubricationUlcerationInfectionVascular insufficiency42Eczema

Quick Quiz: 2 pts each 1. Name 3 of the, at least 8 fxs of integ. system2 . List and describe the 3 layers of the skin3. Name/describe top 2 ways we lose body heat4. Describe keratin and keratinocytes5. Describe the relationship between skin color and melanin

44A pressure ulcer will form where bone causes the greatest force on the skin and underlying tissue.For bedridden persons, most pressure ulcers form on the lower back below the waist, hip bone & heels.

Quick Quiz: cont6. Describe what a sebacious gland is/does7. Describe what a sweat gland is/does8. What does Vit D have to do with skin?9 . Discuss the differences in 1st,2nd, 3rd degree burns10. Discuss two factors that can influence diabetic ulcers and pressure ulcers

45A pressure ulcer will form where bone causes the greatest force on the skin and underlying tissue.For bedridden persons, most pressure ulcers form on the lower back below the waist, hip bone & heels.