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ANATOMYANATOMY
INTEGUMENTARY INTEGUMENTARY SYSTEMSYSTEM
Chapter 4Chapter 4
Classifications of Classifications of MembranesMembranes
EpithelialEpithelial CutaneousCutaneous MucosaMucosa SerousSerous
ConnectiveConnective SynovialSynovial
Cutaneous MembranesCutaneous Membranes Cutaneous- a dry membraneCutaneous- a dry membrane
Outermost protective boundary (skin)Outermost protective boundary (skin)
Superficial epidermisSuperficial epidermis Keratinized Keratinized stratified stratified
squamous epitheliumsquamous epithelium
Underlying dermisUnderlying dermis Mostly dense Mostly dense
connective tissueconnective tissue
MucosaMucosa Surface epitheliumSurface epithelium
Type depends on siteType depends on site
Underlying loose connective Underlying loose connective tissue (lamina propria)tissue (lamina propria)
Lines all body cavities Lines all body cavities that open to the that open to the exterior body surfaceexterior body surface
Often adapted Often adapted for for absorption absorption or secretionor secretion
SerousSerous Surface simple squamous Surface simple squamous
epitheliumepithelium Underlying areolar Underlying areolar
connective tissueconnective tissue Lines open body cavities Lines open body cavities
that are closed to the that are closed to the exterior of the bodyexterior of the body
Serous layers separated by Serous layers separated by serous fluidserous fluid
Specific Serous Specific Serous MembranesMembranes PeritoneumPeritoneum
Abdominal Abdominal cavitycavity
PleuraPleura Around the Around the
lungslungs
PericardiumPericardium Around the Around the
heartheart
Connective- SynovialConnective- Synovial
Synovial Synovial membranemembrane Connective tissue Connective tissue
onlyonly Lines fibrous Lines fibrous
capsules capsules surrounding jointssurrounding joints
Skin’s FunctionsSkin’s Functions Protects deeper tissues from:Protects deeper tissues from:
Mechanical damageMechanical damage Chemical damageChemical damage Bacterial damageBacterial damage Thermal damageThermal damage Ultraviolet radiationUltraviolet radiation DesiccationDesiccation
Aids in heat regulationAids in heat regulation Aids in excretion of urea and uric acidAids in excretion of urea and uric acid Synthesizes vitamin DSynthesizes vitamin D
Skin StructureSkin Structure EpiEpidermis – outer layerdermis – outer layer
Stratified squamous Stratified squamous epitheliumepithelium
Often keratinized Often keratinized (hardened by keratin)(hardened by keratin)
DermisDermis Dense connective tissueDense connective tissue
Hypodermis Hypodermis (Subcutaneous Tissue)(Subcutaneous Tissue)
Below the dermisBelow the dermis Not part of the skinNot part of the skin Anchors skin to Anchors skin to
underlying organsunderlying organs Composed mostly of Composed mostly of
adipose tissueadipose tissue
Layers of the EpidermisLayers of the Epidermis1.1. Stratum basaleStratum basale
Cells undergoing mitosisCells undergoing mitosis Lies next to dermisLies next to dermis
2.2. Stratum spinosumStratum spinosum3.3. Stratum granulosumStratum granulosum4.4. Stratum lucidumStratum lucidum
Occurs only in thick skinOccurs only in thick skin
5.5. Stratum corneumStratum corneum Shingle-like dead cellsShingle-like dead cells
DermisDermis Two layersTwo layers
Papillary layerPapillary layer Projections called dermal papillae (fingerprints!)Projections called dermal papillae (fingerprints!) Pain receptorsPain receptors Capillary loopsCapillary loops
Reticular layerReticular layer Blood vesselsBlood vessels GlandsGlands Nerve receptorsNerve receptors
MelaninMelanin
Pigment produced by Pigment produced by melanocytesmelanocytes Amount produced depends on genetics Amount produced depends on genetics
and sun exposureand sun exposure Yellow, brown, black Yellow, brown, black
colorcolor Found in Found in stratum stratum
basalebasale
Normal Skin Normal Skin DeterminantsDeterminants MelaninMelanin
Yellow, brown or black pigmentsYellow, brown or black pigments
CaroteneCarotene Orange-yellow pigment from some vegetablesOrange-yellow pigment from some vegetables
HemoglobinHemoglobin Red coloring from blood cells in dermis Red coloring from blood cells in dermis
capillariescapillaries Oxygen content determines the extent of red Oxygen content determines the extent of red
coloringcoloring
SWEAT GLANDSSWEAT GLANDS
aka aka sudoriferoussudoriferous glands glands Found over entire skin Found over entire skin
surface except nipples and surface except nipples and part of external genitaliapart of external genitalia
> 2.5 > 2.5 millionmillion per person per person
Eccrine sweat glandsEccrine sweat glands More numerous, Located More numerous, Located
EVERYWHERE!EVERYWHERE! Abundant on Abundant on palms, soles of palms, soles of
feet and foreheadfeet and forehead secretory part of gland coiled in secretory part of gland coiled in
dermisdermis Duct extends to open in a Duct extends to open in a “pore”“pore”
Apocrine sweat Apocrine sweat glandsglands Located in Located in armpit and genitalarmpit and genital areas areas Begin to function at Begin to function at pubertypuberty under under
influence of androgensinfluence of androgens Thought to play role in sexual Thought to play role in sexual
attraction (scent glands in animals)attraction (scent glands in animals) Secrete fatty acids and proteins Secrete fatty acids and proteins
causing a yellowish colorcausing a yellowish color OdorlessOdorless, but bacteria feast on , but bacteria feast on
secretions giving musky odor secretions giving musky odor
Sweat and Its FunctionSweat and Its Function Composition
Mostly water plus salts (NaCl) Some metabolic waste (urea, ammonia, uric
acid) Acidic pH 4-6, inhibits bacteria Fatty acids and proteins (apocrine only)
Function Helps dissipate excess heat Excretes waste products Acidic nature inhibits bacteria growth
SEBACEOUSSEBACEOUS
GLANDSGLANDS
WHAT ARE THEY?WHAT ARE THEY? aka aka oil glandsoil glands secrete an oily substance secrete an oily substance
called called sebumsebum sebum is produced within sebum is produced within
specialized cells and is specialized cells and is released as these cells burst;released as these cells burst;
sebaceous glands are thus sebaceous glands are thus classified as classified as holocrineholocrine glands glands..
Sebum is a Sebum is a mixture of fat and mixture of fat and debris of dead fat-producing cellsdebris of dead fat-producing cells. . These cells are constantly These cells are constantly replaced by new growth at the replaced by new growth at the base of the glands. base of the glands.
sebum is deposited on the hairs sebum is deposited on the hairs inside the follicles and brought up inside the follicles and brought up to the surface of the skin along to the surface of the skin along the hair shaft. the hair shaft.
In hairless areas, the sebum In hairless areas, the sebum surfaces through ducts or poressurfaces through ducts or pores
Sebum acts to Sebum acts to protect and protect and waterproof hairwaterproof hair and skin,and skin, and and keep them from becoming keep them from becoming dry, brittle, and cracked. dry, brittle, and cracked.
It can also inhibit the growth It can also inhibit the growth of microorganisms on skin of microorganisms on skin since it since it contains contains antimicrobial substancesantimicrobial substances
Found everywhere on Found everywhere on the body except the body except the the palms of the hands palms of the hands and soles of the feet.and soles of the feet.
At the rim of the eyelids are a At the rim of the eyelids are a specialized form of sebaceous specialized form of sebaceous gland that secrete sebum into gland that secrete sebum into the tears coating the eye to the tears coating the eye to prevent evaporation.prevent evaporation.
The sebaceous glands of a The sebaceous glands of a human fetushuman fetus in uteroin utero secrete a substance called secrete a substance called vernix caseosavernix caseosa, a "waxy" , a "waxy" or "cheesy" white or "cheesy" white substance coating the skin substance coating the skin of newbornsof newborns
The The activity of the activity of the sebaceous glands sebaceous glands increases during pubertyincreases during puberty because of heightened because of heightened levels of androgens (sex levels of androgens (sex hormones).hormones).
Overactive Overactive sebaceous sebaceous glands can glands can cause skin cause skin problems problems such as such as acneacne..
The extreme use of The extreme use of anabolic steroidsanabolic steroids by by bodybuilders for muscle bodybuilders for muscle gain tend to stimulate the gain tend to stimulate the sebaceous glands which sebaceous glands which can cause acne.can cause acne.
A blocked sebaceous gland A blocked sebaceous gland can result in a can result in a sebaceous cystsebaceous cyst..
Dry skin is caused by Dry skin is caused by underactive oil glands underactive oil glands
as we get older, as our bodies as we get older, as our bodies don't produce these natural oils don't produce these natural oils so effectively. so effectively.
Babies and young children are Babies and young children are also often susceptible to dry skin also often susceptible to dry skin because the sebaceous glands because the sebaceous glands haven't developed properly. haven't developed properly.
Appendages of the SkinAppendages of the Skin HairHair
Produced by hair Produced by hair bulbbulb
Consists of hard Consists of hard keratinized keratinized epithelial cellsepithelial cells
MelanocytesMelanocytes provide pigment provide pigment for hair colorfor hair color
Figure 4.7c
Hair AnatomyHair Anatomy
Central medullaCentral medulla Cortex surrounds Cortex surrounds
medullamedulla Cuticle on outside of Cuticle on outside of
cortexcortex Most heavily Most heavily
keratinizedkeratinized
Figure 4.7b
Associated Hair Associated Hair StructuresStructures
Hair follicleHair follicle Dermal and epidermal Dermal and epidermal
sheath surround hair rootsheath surround hair root
Arrector pilliArrector pilli Smooth muscleSmooth muscle Lifts hair uprightLifts hair upright, ,
““goosebumpsgoosebumps””
Sebaceous glandSebaceous gland Sweat glandSweat gland
Figure 4.7a
Appendages of the SkinAppendages of the Skin
NailsNails Scale-like modifications of the Scale-like modifications of the
epidermisepidermis Heavily keratinizedHeavily keratinized
Stratum basaleStratum basale extends beneath the extends beneath the nail bednail bed Responsible for growthResponsible for growth
Lack of pigment makes them colorlessLack of pigment makes them colorless
Nail StructuresNail Structures
Free edgeFree edge BodyBody Root of nailRoot of nail Eponychium Eponychium
– proximal – proximal nail fold that nail fold that projects onto projects onto the nail bodythe nail body
Figure 4.9
Skin Homeostatic Skin Homeostatic ImbalancesImbalances
InfectionsInfections Athletes footAthletes foot
Caused by fungal infectionCaused by fungal infection
Boils and carbunclesBoils and carbunclesCaused by bacterial infectionCaused by bacterial infection
Cold soresCold soresCaused by virusCaused by virus
Skin Homeostatic Skin Homeostatic ImbalancesImbalances
Infections and allergiesInfections and allergies Contact dermatitisContact dermatitis
Exposures cause allergic reactionExposures cause allergic reaction
ImpetigoImpetigo Caused by bacterial infectionCaused by bacterial infection
PsoriasisPsoriasis Cause is unknownCause is unknown Triggered by trauma, infection, stressTriggered by trauma, infection, stress
BURNS BURNS
AND AND
SKIN SKIN CANCERSCANCERS
BURNSBURNS
BURNSBURNSWhat are they?What are they?What causes them?What causes them?
A burn is A burn is damage to your damage to your body's tissues caused by body's tissues caused by heat, chemicals, heat, chemicals, electricity, sunlight or electricity, sunlight or radiation. radiation.
Scalds from hot liquids Scalds from hot liquids and steam, building and steam, building fires and flammable fires and flammable liquids and gases are liquids and gases are the the most common most common causescauses of burns. of burns.
There are There are three types of three types of burnsburns depending on how depending on how severe the burn is and its severe the burn is and its damage to underlying damage to underlying tissues:tissues:
First degreeFirst degree Second degreeSecond degree Third degreeThird degree
Rule of NinesRule of Nines
Way to determine Way to determine the extent of the extent of burnsburns
Body is divided Body is divided into 11 areas for into 11 areas for quick estimationquick estimation Each area Each area
represents about represents about 9%9%
First-degree burnsFirst-degree burns
damage only thedamage only the outer outer layer of skin-layer of skin-thethe epidermis epidermis
Only symptom is Only symptom is redness redness of skinof skin
are are painfulpainful
Example: sunburnExample: sunburn
Second-degree burnsSecond-degree burns damage the damage the epidermis epidermis
andand the the dermisdermis Causes Causes blistersblisters to form as to form as
epidermis epidermis separatesseparates from from the dermisthe dermis
Also Also painfulpainful
Second Second degree degree burnsburns
Third-degree burnsThird-degree burns
damage or destroy damage or destroy both layers both layers of skin and tissues of skin and tissues underneathunderneath
patients often require patients often require skin skin graftsgrafts
usually usually painless painless because the because the nerve endingsnerve endings that supply that supply pain sensation pain sensation areare destroyeddestroyed
Third degree burnsThird degree burns
Burns can cause swelling, Burns can cause swelling, blistering, scarring and, in serious blistering, scarring and, in serious cases, shock and even death.cases, shock and even death.
Swelling and blistering come from Swelling and blistering come from fluids seeping out of the blood fluids seeping out of the blood vesselsvessels
This fluid loss creates one of the This fluid loss creates one of the greatest dangers from burns-greatest dangers from burns-fluid fluid lossloss and and dehydration.dehydration.
Fluid loss can be so great as Fluid loss can be so great as to lead to depletion of blood to lead to depletion of blood volume and shock and volume and shock and dangerously low blood dangerously low blood pressurepressure
Death is likely if the fluids Death is likely if the fluids are not replenished (are not replenished (IV fluid IV fluid replacementreplacement with isotonic with isotonic saline or plasma)saline or plasma)
Another great danger Another great danger of burns is of burns is infectioninfection because they damage because they damage your skin’s protective your skin’s protective barrier. Antibiotic barrier. Antibiotic creams can prevent or creams can prevent or treat infectionstreat infections.. ..
11stst and 2 and 2ndnd degree degree burns can heal over burns can heal over time without skin time without skin grafts since there is grafts since there is enough underlying skin enough underlying skin to repair the skin.to repair the skin.
After a third-degree After a third-degree burn, burn, skinskin or or synthetic synthetic graftsgrafts may be needed may be needed to cover exposed tissue to cover exposed tissue and encourage new skin and encourage new skin to grow. to grow.
This is as good as it will ever get. These scars are for life!
SKIN SKIN CANCERSCANCERS
Basal Cell CarcinomaBasal Cell Carcinoma
Least malignant but MOST COMMONLeast malignant but MOST COMMON Sun exposed areasSun exposed areas Invade the dermis and hypodermisInvade the dermis and hypodermis
Squamous Cell carcinomaSquamous Cell carcinoma
Scaly, reddend papuleScaly, reddend papule Sun-induced, metastasizes to lymph nodesSun-induced, metastasizes to lymph nodes
Malignant MelanomaMalignant Melanoma
Cancer of MelanocytesCancer of Melanocytes Only 5% of cancers, but increasingOnly 5% of cancers, but increasing MOST DEADLY (survival 50%)MOST DEADLY (survival 50%) Some develop from molesSome develop from moles
ABCD’sABCD’s A= AsymmetryA= Asymmetry
2 sides do not match2 sides do not match
B= Border IrregularityB= Border Irregularity Not smooth, indentationsNot smooth, indentations
C= ColorC= Color Different colors: reds, tans, blacks, brownDifferent colors: reds, tans, blacks, brown
D= DiameterD= Diameter larger than 6mmlarger than 6mm
E= EvolutionE= Evolution