Skin is the largest organFunction and Structure and of the body,serves to:•Protect against injury•Protect against the sun UV rays•Prevent entry of harmful microorganisms•Maintain the proper internal bodytemperature•Excrete waste materials throughperspiration•Function as a sense organ 2
Three Layers of theSkin Three Layers of SkinEpidermisDermis Nerves, vessels, glands, hair folliclesSubcutaneous/Hypodermis 3
epidermis EpidermalEpidermal Layer Layer•Outermost skin layer•Consists of severalsublayers•Keratin – protein thatmakes skin tough andwaterproof by preventingfluids et al from passingthrough the skin •Constantly replaced •Melanin – pigment that gives skin its color 4
Dermal Layer Dermal Layer dermis •“True skin” •Holds many capillaries, lymph cells, nerve endings, sebaceous and sweat glands and hair follicles •Arrector pili – cause goosebumps•Touch, temperature and •Thermoregulationpain sensation originate •Perspirationfrom dermis nerve cells •3rd degree burns 5
Subcutaneous Layer Subcutaneous Layer•Also called the hypodermis•Found between the dermal layerand the inner organs•Consists mostly of fatty tissues •Fatty tissue protects inner organs, maintains body temperature and stores energy •Blood vessels and nerves are present subcutaneous 6
Hair Hair - Protect and insulate•Grows out of the epidermis to cover parts of thebody. •The shaft is what we see and the root lies below the surface of the skin. Hair color is determined by the presence of melanin. Baldness or alopecia may result from heredity, disease, injury, or chemotherapy. 7
Nails Nails•Nails are plates madeof hard keratin uppersurface of the fingersand toes.•Grows throughout life•At the base of most nails a lunula or whitishhalf-moon is an area where keratin and othercells have mixed with air.•The cuticle is a narrow band of epidermis thatsurrounds the base or bottom of nails. 8
Glands Glands•Sebaceous glands secrete sebum outwardtoward the surface of the body and are locatedalmost everywhere on the body.•Sweat glands maintain normal temperaturethrough perspiration Types of sweat glands Eccrine ApocrineProduce sweat to cool body Produce sweat of no useForehead, palms and soles Armpits, genitals 9
Other ConditionsOther Conditions•Impetigo, a highly contagious skin condition iscaused by staphylococci and characterized by thepresence of pus.•Ringworm or tinea is caused by fungi, and ischaracterized by intense itching or pruritis.•Common rashes such as diaper rashes are alsocaused by fungi known as Candidiasis. 11
Common FungiOther Common Fungi•tinea pedis (athlete’s foot)•tinea capitis (scalp ringworm)•tinea barbae (ringworm of the beard) 12
Vascular ConditionsVascular Conditions •Ecchymosis Bluish-purple skin mark may be due to injury. •Petechiae Tiny pinpoint ecchymosis. •Purpura Extensive skin hemorrhages covering a wide area. •Rosacea Appears as red blotches on the skin, 13 especially the nose and cheeks.
Skin Conditions Related toSkin Conditions Related to Pigmentation Pigmentation•Leukoderma•Vitiligo•Albinism•Chloasma Vitiligo 14
Categories of BurnsBurns to the skin may result from exposure to heat,chemicals, electricity, radiation or other irritants.Categories of Burns•First Degree •Third Degreeis superficial, without involves completeblistering, but with destruction of skinredness and swelling. and sometimes reaches muscle •Second Degree and bone. involves the epidermis and dermis and blistering. 15
Conditions Caused by Insects Some skin conditions are caused by insects. PediculosisAn inflammation with Scabieslice usually on the Contagious skinhead or genitals. eruption that often occurs between fingers, on areas of the trunk, or male genitalia and is caused by mites. 16
Surgical TermsVarious types of plastic surgery may involvereconstructing areas of the skin. Other typesinvolve removing part of a growth to test forcancer or removing the entire cancerous growth. 17
Apply Your Knowledge Part 2 Which of the following patients would experience the most pain following their burn injury?Patient A accidentally spilled hot grease on hishis right hand and arm resulting in first andsecond degree burns to the entire area. -OR-Patient B was in his home when his keroseneheater fell on his left lower leg causing completethird degree burns to the area. Answer: Patient A 18
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