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Integumentary System. What is skin?. Largest single organ in the body Covers the body Integument means “covering” Major functions: Protects the body from mechanical, chemical, bacterial, UV, thermal damage Protects the body from desiccation (drying out) Assists in body heat regulation
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What is skin? • Largest single organ in the body • Covers the body • Integument means “covering” • Major functions: • Protects the body from mechanical, chemical, bacterial, UV, thermal damage • Protects the body from desiccation (drying out) • Assists in body heat regulation • Make Vitamin D • Excrete Urea & uric acid
Protect from Damage • Mechanical – bumps & injury • Chemical – acid & bases • Bacterial – infections • UV – sunlight • Thermal – climate elements (heat & cold) • Keratin – is in the outer layer to prevent water loss from body surface
Body heat & Excretion • Sweat is secreted to cool the body • Consists of urea, uric acid, water, & salt • When the body is cold, the blood is shifted away from the skin to keep vital organs warm. • What color does the skin become when you are cold?
Vitamin D • Cholesterol that is present in the skin (calciferol) • Ultraviolet light (sunlight) converts the cholesterol into Vitamin D • Is Fat Soluble vitamin • Helps the body to maintain the appropriate levels of Calcium (Ca) & Phosphorus (Ph) • Vitamin D must be present for Calcium to be absorbed
The application of sunscreen with an SPF factor of 8 reduces production of vitamin D by 95% creating a similar problem to covered skin.1
Layers of the skin • Epidermis – the outermost layer of skin • No nerves or blood vessels • 2 layers • Stratum corneum – outer layer & constantly shed cells • Stratum germinativum – inner layer & replaces cells of the corneum
Layers of the skin • Dermis (corium)– “true skin” • Contains blood vessels, lymph vessels, nerves, sweat glands, oil glands, & hair follicles • Papillae cover the dermis to “fit” into the stratum germinativum & form lines (fingerprints, footprints) • Subcutaneous fascia (hypodermis) – • Elastic & fibrous connective tissue • Fat tissue • Connects the skin to muscle
Melanin • Pigmentation that ranges from yellow to brown to black • Made by cells called melanocytes in the epidermis • Sunlight stimulates the melanocytes to produce melanin • Protects the cells’ DNA from damage • Freckles & moles – concentrated spots of melanin
Skin colors • Red – due to increased blood flow & the visualization of blood through the dermis • Embarrassment • Fever • Inflammation • Allergies • Hypertensions (HTN)
Pallor (paleness) – Paleness • Emotional stress • Anemia • Low blood pressure • Impaired circulation • Yellow – jaundice • Liver dysfunction & elevated bilirubin • Black & Blue – blood has escaped circulation & clotted in tissue • Decreased level in Vitamin C • Injury
Sweat glands • Also know sudoriferous • Over 2.5 million glands per person • 2 types • Eccrine • Found all over body • Produce sweat • Water, salt, vitamin C, ammonia, urea, uric acid, lactic acid • Acidic (4 – 6 ph) that inhibits bacteria growth • Pores that secrete sweat have nerves that detect external temperature • Body can lose up to 7 liters of water through sweat
Apocrine glands • In axillary & genital area • Larger than eccrine • Empty into hair follicles • Secrete fatty acids & proteins (milky or yellow) • Begin secreting in puberty
Hair follicles • Composed of epithelial tissue & form hair • Outer portion provides the blood supply to inner portion to make hair • Smooth muscles called arrector pili connect each follicle to the dermal tissue • When the muscle contracts, the hair pulls up “goose bumps”
Nails • Modified epidermis that is similar to a hoof or claw of an animal • Transparent but appear pink due to the blood supply underneath
Sebaceous glands • Oil glands that open onto hair follicles • Provide oil to hair & skin to prevent drying • Slightly acidic to prevent infection
Conditions of the skin • Acne • Acne Vulgaris • Inflammation of the sebaceous glands • Cause is unknown • Symptoms – papules, pustules, & blackheads • Hair follicles get blocked by dirt, cosmetics, excess oil, bacteria • Treatment: skin washing, antibiotic, vitamin A ointments, UV treatment
Eczema • Noncontagious • Usually caused by allergen or irritant (soaps, medication, diet, stress) • Symptoms • Dryness • Erythema – redness • Edema • Itching, crusty, scaly skin • Treatment – corticosteroids & hydration
Cold Sores • Caused by herpes simplex 2 • Fluid – filled blisters • Itch & sting • Localizes at the nerve • Be aggravated by: • Emotional upset • Fever • UV radiation
Warts • Verrucae • Viral infection on the skin • Rough, hard elevated rounded surface • Disappear spontaneously • Can be removed by liquid nitrogen, electricity, acid, chemicals, laser
Skin Cancer • Most common type of cancer • 3 types • Basal cell carcinoma • Basal cells of the epidermis • Grow slowly & does not usually spread • Pink to yellow & depressed center with elevated borders • Squamous cell carcinoma • Thin cells of epithelium • Spreads to other areas • Red flat sores that later scale & crust or sores that do not heal
Melanoma • Cancer in the melanocyte • Most dangerous • Lesions are brown, black, pink, or multicolored • Frequently develop in moles • These change colors, shape, size, & texture • Caused by prolonged sun exposure, tanning beds, radiation • Treatment: surgical removal, radiation, chemotherapy
Burns • A burn is damage to your body's tissues caused by heat, chemicals, electricity, sunlight or radiation. Scalds from hot liquids and steam, building fires and flammable liquids and gases are the most common causes of burns. • 1st degree • 2nd degree • 3rd degree
1st degree • Only damages the outer layer of the skin • Sunburn • The inflammation is characterized by pain, redness, and a mild amount of swelling. The skin may be very tender to touch.
2nd degree • damage the outer layer and the layer underneath • deeper and in addition to the pain, redness and inflammation, there is also blistering of the skin.
3rd degree • damage or destroy the deepest layer of skin and tissues underneath • involving all layers of the skin, in effect killing that area of skin. Because the nerves and blood vessels are damaged, third degree burns appear white and leathery and tend to be relatively painless.
Burn Healing • Regardless of the type of burn, inflammation and fluid accumulation in and around the wound occur. Moreover, it should be noted that the skin is the body's first defense against infection by microorganisms. A burn is also a break in the skin, and the risk of infection exists both at the site of the injury and potentially throughout the body. • Only the epidermis has the ability to regenerate itself. Burns that extend deeper may cause permanent injury and scarring and not allow the skin in that area to return to normal function.
Assessment • Visualization • Your eyes are very important in assessing the skin.