Chapter 05 Lecture Outline See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes.
Chapter 5-Integumentary System • What does integument mean?
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covering $airs
• Components: – skin – hair – nails – glands
#pidermis
Sebaceous gland
%rrector pili (smooth muscle
S!in
"ermis
$air follicle 'ere &ein %rtery Sweat gland %dipose tissue
Subcutaneous tissue (hypodermis
Chapter 5-Integumentary System • What does integument mean?
Copyright © The McGraw-Hill Companies, Inc. Permission required or reproduction or display.
covering $airs
• Components: – skin – hair – nails – glands
#pidermis
Sebaceous gland
%rrector pili (smooth muscle
S!in
"ermis
$air follicle 'ere &ein %rtery Sweat gland %dipose tissue
Subcutaneous tissue (hypodermis
Functions 1. Protection:
water loss, microbes, UV light 2. Sensation:
hot, cold, pain, pressure 3. Te Temperature mperature regulation: regulation:
helps maintain homeostasis
4. !cretion:
removes waste 5. "itamin # pro$uction:
UV light stimulates production
S%in Facts • Weighs " lbs# • Used to determine bod$ %at • & main regions: epi$ermis and $ermis
pi$ermis • 1st ma&or s%in region 'outsi$e( • Composed o% strati%ied s(uamous epithelium • )eratini*ation: - process in which new cells )with keratin* push
old cells to sur%ace + +!- da$s %or new cells to reach sur%ace
Strata o+ pi$ermis • Stratum corneum: + outermost la$er o% epidermis + &+3 la$ers o% dead s(uamous cells %illed with keratin + accounts %or '!/ o% epidermal thickness + $an$ru++ is this la$er %laking o%% scalp • Callus: %orms when stratum corneum has %re(uent %riction
• Stratum ,asale: - deepest la$er o% epidermis
+ single la$er o% cells + %irml$ attached to dermis
#ermis • 2n$ ma&or s%in region • 1ense connective tissue • Contains collagen and elastic %ibers • Contains %ibroblasts, nerve endings, smooth muscle, glands, blood vessels, and hair %ollicles • Cleaage lines: - area where skin is most resistant to stretching
+ due to orientation o% collagen %ibers + important in scarring
ayers o+ #ermis • Papillary layer: + thin connective tissue la$er that contains blood
vessels - #ermal papillae:
+ pro2ections that etend up into epidermis + remove waste and help regulate bod$ temp# + ridged on hands and %eet )%ingerprints* + pattern is geneticall$ determined
• /eticular layer: + deepest la$er o% dermis + accounts %or ./ o% dermis
0ypo$ermis • • • • • •
4elow dermis 5oundation o% skin 6ttaches skin to underl$ing muscle and bone Contains loose and adipose tissue Contains 7 o% bod$8s %at 4od$ %at %or %emales &+&3/, males 03+&!/
S%in Color an$ "ariations • #etermine$ ,y: - pigments + genetics + blood circulation + thickness o% stratum corneum • 9elanoc$tes o% darker skinned people produce more and darker melanin than %airer skinned people • ll races hae same num,er o+ melanocytes
S%in Pigments •
elanin: - produced b$ melanocytes
+ ranges %rom $ellow to reddish+brown to black + responsible %or hair and e$e color + provides protection against UV light + amt# produced determined b$ genetics, UV light,
hormones + %reckles are accumulation o% melanin + albinism is absence o% melanin
•
Carotene: - $ellow+orange pigment %ound in plants
+ accumulates in stratum corneum •
0emoglo,in:
+ gives pinkish+red color + %ound in red blood cells
Tanning an$ Sun,urns • posure to UV light stimulates melanoc$tes to increase production o% melanin • 9elanin builds up to help protect skin against UV radiation )tan* • 6 sunburn is the skin reacting to UV eposure • UV light causes elastic %ibers to clump and become leather$ • UV light can alter 1;6 in cells causing them to mutate )cancer*
S%in Color an$ #isease • /e$ness: %ever, h$pertension, in%lammation, allergies • Pallor: anemia or low blood pressure • aun$ice: liver disorder )$ellow* • ron*ing: 6ddison8s disease )kidne$ disease* • ruising:
0air Components • 0airsha+t: %leible strands o% keratini
• 0air ul,: - base o% root
+ where hair is produced • 0air Follicle: + group o% cells that surround root and bulb + gives hair di%%erent shapes
0o6 is 0air Pro$uce$7 •
=air is produced in hair ,ul,
•
=air bulb rests on blood vessels to suppl$ it with nutrients
•
=air grows longer as cells are added to base o% hair bulb
0air Facts • >estosterone and good nutrition promote hair growth • rowth occurs in c$cles: active and resting • @calp hair grows %or 3 $ears and rests %or 0 $ear • $elashes grow %or 3 da$s and rest %or 0! da$s • We lose about " scalp hairsAda$ • re$ hair is the loss or %ading o% melanin • 9ale pattern baldness is %rom the loss o% the hair %ollicle
0air uscles • rrector Pili: + smooth muscle that surrounds each hair %ollicle + contracts and hair stands on end )goose bumps*
8lan$s • Se,aceous glan$s: + connected to hair %ollicle + se,um: oil$ substance that lubricates hair and skin to prevent dr$ing • ccrine s6eat glan$s: + all over bod$ and open into sweat pores + water and salt secretions
• pocrine s6eat glan$s: + open into hair %ollicle + onl$ in armpits and genitalia + thick, rich secretions + become active during pubert$ and cause bod$ odor
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Sweat pores "uct of eccrine sweat gland "uct of apocrine sweat gland
%rrector pili (smooth muscle
$air follicle
Sebaceous gland
$air bulb
#ccrine sweat gland
9ails • hat are they7 thin plate with la$ers o% dead stratum corneum cells with hard keratin
9ail Structure • 9ail ,o$y: visual part • 9ail root: covered b$ skin • Cuticle: stratum corneum that etends into nail bod$
• 9ail matri!: - continuation o% nail root
+ gives rises to most o% nail • 9ail ,e$: attaches to nail and is distal to nail matri • unula: + part o% nail matri + whitish, crescent shaped area + base o% nail
"itamin # Pro$uction 0# UV light causes skin to produce a precursor molecule o% vitamin 1 &# Brecursor is carried b$ blood to liver where it is modi%ied 3# ;et to kidne$s where it is modi%ied again to %orm active vitamin 1 • "itamin # can also ,e ingeste$ through +ish oils; +orti+ie$ mil%; eggs; an$ ,utter. • "itamin # stimulates intestine to a,sor, calcium an$ phosphate ',one gro6th an$
Temperature /egulation • 4od$ temp# should be ".#- C o
• ate o% chemical reactions )metabolism* is altered b$ changes in temp# • To cool ,o$y: blood vessels in dermis dilate and heat is trans%erred %rom deep in tissues to skin and sweat is produced • Too heat ,o$y: blood vessels constrict to reduce blood %low to
ging an$ the Integument • 4lood %low decreases and skin becomes thinner due to decreased amounts o% collagen • 1ecreased activit$ o% sebaceous and sweat glands make temperature regulation more di%%icult • Doss o% elastic %ibers cause skin to sag and wrinkle
Classi+ication o+ urns • 1st $egree: + damages onl$ epidermis + redness, slight swelling, pain + heals within &+3 da$s )usuall$ no scar* + includes sunburns or eposure to cold
• 2n$ $egree: + damages epidermis and upper dermis + redness, swelling, pain, blisters heals in & weeks with some scarring
• 3r$ $egree: + destro$s epidermis and dermis + burned areas are cherr$ red to black + nerve endings are destro$ed + skin gra%t might be necessar$
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#pidermis
"ermis
Partialthic!ness
)ullthic!ness
)irst- Seconddegree degree
*hirddegree
S%in Cancer • 9ost common cancer • 9ainl$ caused b$ UV light eposure • 5air+skinned people more prone • Brevented b$ limiting sun eposure and using sunscreens • UV6 ra$s cause tan and is associated with malignant melanomas • UV4 ra$s cause sunburns • @unscreens should block UV6 and UV4 ra$s
Types o+ S%in Cancer • asal cell carcinoma: - cells in stratum basale a%%ected
+ cancer removed b$ surger$ • S
