INTEGUMENTARY INTEGUMENTARY SYSTEMSYSTEM

SKINSKIN

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BODY MEMBRANESBODY MEMBRANES

MEMBRANESMEMBRANES• Structure: Thin, sheet like structureStructure: Thin, sheet like structure• Functions:Functions:

– Cover and protect the body surfaceCover and protect the body surface– Line the body cavitiesLine the body cavities– Cover the inner surface of the hollow Cover the inner surface of the hollow

organs (digestive, reproductive, organs (digestive, reproductive, respiratory)respiratory)

– Anchor organs to each other or to bonesAnchor organs to each other or to bones– Cover internal organsCover internal organs– Secrete lubricating fluids that reduce Secrete lubricating fluids that reduce

friction during organ movementsfriction during organ movements

Two Types of Body Two Types of Body MembranesMembranes

• Epithelial MembranesEpithelial Membranes– Cutaneous membrane (skin)Cutaneous membrane (skin)– Serous membranes (protection/reduce Serous membranes (protection/reduce

friction for organs)friction for organs)– Mucous membrane (line body surfaces Mucous membrane (line body surfaces

opening directly to the exterior– such as opening directly to the exterior– such as the esophagus; mucus secretion) the esophagus; mucus secretion)

• Connective Tissue Membrane (no Connective Tissue Membrane (no epithelium)epithelium)– Smooth & slick, secrete synovial fluidSmooth & slick, secrete synovial fluid– Reduce friction b/w opposing bones, line Reduce friction b/w opposing bones, line

bursa sacsbursa sacs

SEROUS MEMBRANESSEROUS MEMBRANES

• Two Layers:Two Layers:– Visceral: covers the surface of the organVisceral: covers the surface of the organ– Parietal: lines the walls of the body cavityParietal: lines the walls of the body cavity

• Thoracic Cavity=PleuraThoracic Cavity=Pleura• Abdominal Cavity=PeritoneumAbdominal Cavity=Peritoneum

– Describe the following:Describe the following:• Visceral pleura, parietal pleuraVisceral pleura, parietal pleura• Visceral peritoneum, parietal peritoneumVisceral peritoneum, parietal peritoneum

– What is pleurisy? What is peritonitis?What is pleurisy? What is peritonitis?

SKINSKIN

• FUNCTIONSFUNCTIONS– Protection against microbes, UV rays, Protection against microbes, UV rays,

harmful chemicals, cuts & tearsharmful chemicals, cuts & tears– Temperature regulationsTemperature regulations– Sense organ activity: touch, pressure, Sense organ activity: touch, pressure,

pain, temperaturepain, temperature– Metabolic functions: synthesis of Metabolic functions: synthesis of

vitamin Dvitamin D

Skin: StructureSkin: Structure• Two Layers:Two Layers:

– Epidermis Epidermis • outermost & thinnestoutermost & thinnest• cells are very tightly packedcells are very tightly packed

– Dermis Dermis • deep & thickdeep & thick• primarily connective tissueprimarily connective tissue• loosely packedloosely packed

• Hypodermis (adipose tissue)Hypodermis (adipose tissue)– Deep to the skin/dermisDeep to the skin/dermis– Layer of insulationLayer of insulation

EpidermisEpidermis• Stratum corneumStratum corneum

– Dry, dead, keratin Dry, dead, keratin filled cellsfilled cells

• Statum Statum germinativum/basalgerminativum/basalee– Cells undergoing Cells undergoing

mitosis, move up mitosis, move up

EpidermisEpidermis

• Specialized cells within epidermis:Specialized cells within epidermis:– MelanocytesMelanocytes

• Melanin: pigment, inc. w/sun (protection)Melanin: pigment, inc. w/sun (protection)

– KeratinocytesKeratinocytes• Keratin: tough, waterproof material; Keratin: tough, waterproof material;

abrasion resistance for cells abrasion resistance for cells

– Langerhans cellsLangerhans cells• Immune response against microbes Immune response against microbes

invading the skininvading the skin

DermisDermis• Collagen, elastin fibers– scatteredCollagen, elastin fibers– scattered

Dermal-epidermal Dermal-epidermal junctionjunction

• Dermal papillae: parallel rows of Dermal papillae: parallel rows of peg-like projectionspeg-like projections– Unique to each individual=FingerprintsUnique to each individual=Fingerprints

DermisDermis

• Specialized structures:Specialized structures:– Hair follicle: cells of the epidermis Hair follicle: cells of the epidermis

extend into the dermis forming a small extend into the dermis forming a small tubetube

– Hair bulb: base of the follicleHair bulb: base of the follicle– Hair papilla: cluster of cells (live); Hair papilla: cluster of cells (live);

nourished by BV’snourished by BV’s– Root: part of hair hidden in follicleRoot: part of hair hidden in follicle– Shaft: visible part of hairShaft: visible part of hair

DermisDermis• Specialized Structures (continued)Specialized Structures (continued)

– Arrector pili: tiny, smooth muscle Arrector pili: tiny, smooth muscle attached to base of dermal papillae & attached to base of dermal papillae & side of hair follicelside of hair follicel• Contracts: pulls on both Contracts: pulls on both

simultaneously>>goosebumpssimultaneously>>goosebumps

Specialized Structures of Specialized Structures of the Dermisthe Dermis

• Sebaceous GlandsSebaceous Glands– Secrete oil (sebum) for hair/skinSecrete oil (sebum) for hair/skin– Ducts open into hair folliclesDucts open into hair follicles– Accumulated sebum enlarges Accumulated sebum enlarges

ducts>>white headsducts>>white heads– Darkened sebum>>black headDarkened sebum>>black head

Specialized Structures of Specialized Structures of DermisDermis

• Sudoriferous GlandsSudoriferous Glands– Eccrine GlandsEccrine Glands

• WidespreadWidespread• Watery FluidWatery Fluid

– Apocrine GlandsApocrine Glands• Armpits/GenitalsArmpits/Genitals• Thick/milky fluidThick/milky fluid

Pacinian Corpuscle: deep in Pacinian Corpuscle: deep in the dermis; detects the dermis; detects

pressurepressure

Close to the surface; Close to the surface; light touchlight touch

Krause’s end bulb: touch/ Krause’s end bulb: touch/ low frequency vibration; low frequency vibration;

coldcold

Thin Light SkinThin Light Skin

Thick Light SkinThick Light Skin

First Degree Burn: First Degree Burn: Epidermis onlyEpidermis only

First Degree BurnFirst Degree Burn

First Degree BurnFirst Degree Burn

Second Degree Burn: Second Degree Burn: Epidermis and upper layers Epidermis and upper layers

of the dermisof the dermis

Second Degree BurnSecond Degree Burn

Third Degree Burn: Complete Third Degree Burn: Complete destruction of the epidermis destruction of the epidermis

& dermis& dermis

Third Degree BurnThird Degree Burn

Third Degree BurnsThird Degree Burns

Third DegreeThird Degree

RegenerationRegeneration

Regeneration/ScarringRegeneration/Scarring

Skin graft donor site: about Skin graft donor site: about halfway through the initial halfway through the initial

healing stagehealing stage

PapulePapule

• Firm, raised lesion (less than 1cm in Firm, raised lesion (less than 1cm in diameter)diameter)

PapulePapule

PlaquePlaque

• Large, raised lesion (greater than 1 Large, raised lesion (greater than 1 cm in diameter)cm in diameter)

PlaquePlaque

VesicleVesicle

• Thin-walled blister filled w/ fluid, Thin-walled blister filled w/ fluid, <1cm<1cm

VesicleVesicle

PustulePustule

• Elevated lesion filled w/ pusElevated lesion filled w/ pus

PustulePustule

CrustCrust

• Scab, area w/ dried blood or exudateScab, area w/ dried blood or exudate

WhealWheal

• Firm, raised area of irregular Firm, raised area of irregular shape/light centershape/light center

WhealWheal

MaculeMacule

• Distinguished from surrounding skin Distinguished from surrounding skin by colorby color

MaculeMacule

ExcoriationExcoriation

• Epidermis is missing, dermis is Epidermis is missing, dermis is exposedexposed

ExcoriationExcoriation

UlcerUlcer

• Craterlike lesion caused by Craterlike lesion caused by disintegration of the skindisintegration of the skin

UlcerUlcer

Bed SoreBed Sore

FissureFissure

• Linear crack or break from Linear crack or break from epidermis to dermisepidermis to dermis

FissuresFissures