SKIN Layers of Skin Epidermis Dermis Hypodermis

SKINSKIN

Layers of SkinLayers of SkinEpidermis

Dermis

Hypodermis

Facts about the skinFacts about the skin

Different thickness -.5mm (eyelid) Different thickness -.5mm (eyelid) to 5mm (middle of your backto 5mm (middle of your back

21.5 square feet surface of your 21.5 square feet surface of your body.body.

Skin is the largest organ of the Skin is the largest organ of the body.body.

EpidermisEpidermis Greek = epi, over & derma, skin.Greek = epi, over & derma, skin. Top layer of epidermis is called Stratum Top layer of epidermis is called Stratum

corneum - soft keratin which keeps the corneum - soft keratin which keeps the skin elastic.skin elastic.

Stratum lucidum -has translucent layers of Stratum lucidum -has translucent layers of dead cell that contain protein called eleidin dead cell that contain protein called eleidin which is only in the palms of the hands which is only in the palms of the hands and soles of the feet.and soles of the feet.

More Layers of epidermisMore Layers of epidermis

Stratum granulosumStratum granulosum - layer of dying cells - layer of dying cells Stratum spinosumStratum spinosum - interlocking spine- - interlocking spine-

like projections help support this binding like projections help support this binding layer.layer.

Stratum basaleStratum basale -basement next to the -basement next to the dermis. Continuous cell division - new dermis. Continuous cell division - new cells are made. Where melanocytes are cells are made. Where melanocytes are found.found.

DermisDermisMeans True SkinMeans True SkinPapillary layerPapillary layerReticular layerReticular layerHypodermis layerHypodermis layer

Papillary layerPapillary layerLoose connective tissueLoose connective tissuePapillae helps to join to Papillae helps to join to

epidermisepidermisDouble layers in hands and Double layers in hands and

solessolesCauses finger printsCauses finger printsAids in gripping surfacesAids in gripping surfaces

Reticular layerReticular layerDense connective tissueDense connective tissueCoarse caliginous fibers Coarse caliginous fibers

and bundlesand bundlesFibers crisscross forming a Fibers crisscross forming a

strong, elastic layerstrong, elastic layer

Reticular layerReticular layerWhere most of the gland and Where most of the gland and

things are located.things are located.HairHairOil glandOil glandCorpuscles of touchCorpuscles of touch

HypodermisHypodermisAlso known as Also known as Subcutaneous layerSubcutaneous layerLies beneath the dermisLies beneath the dermisComposed of loose, fibrous Composed of loose, fibrous

connective tissueconnective tissueThicker than the dermisThicker than the dermisLarge supply of lymphatic and Large supply of lymphatic and

blood vesselsblood vessels

HypodermisHypodermisSweat glands (sudoriferous)Sweat glands (sudoriferous)Base of hair folliclesBase of hair folliclesCan be tight or looseCan be tight or looseMore hypodermis give us More hypodermis give us

paddingpaddingHeelsHeelsBreastBreast

Function of SkinFunction of SkinTemperatureTemperature

SweatSweatConstriction & dilation of blood Constriction & dilation of blood

vesselsvesselsGoose bumpsGoose bumps

ExcretionExcretionSweatSweat1g nitrogen every hour1g nitrogen every hour

More FunctionsMore FunctionsSynthesisSynthesis

Vitamin D - makes strong bones Vitamin D - makes strong bones and teethand teeth

Helps to prevent RicketsHelps to prevent RicketsSensory receptionSensory reception

Heat & coldHeat & coldTouch & pressureTouch & pressurePainPain

Color of SkinColor of SkinPresence of MelaninPresence of Melanin

Dark skinned people produce Dark skinned people produce moremore

Asian people have very little Asian people have very little Accumulation of caroteneAccumulation of caroteneBlood reflected through Blood reflected through

epidermisepidermis

Platelets (thrombocytes) and Platelets (thrombocytes) and fibrinogen form a netfibrinogen form a net

Less than 24 hrs. becomes dehydrated Less than 24 hrs. becomes dehydrated and a scab forms.and a scab forms.

Two or three days after the wounding, Two or three days after the wounding, monocytes enter the wound.monocytes enter the wound.

About 10 days after, epidermis is About 10 days after, epidermis is restored & the scab is gone. Tough restored & the scab is gone. Tough scar tissue continues to form.scar tissue continues to form.

Sudoriferous (Sweat) GlandSudoriferous (Sweat) Gland

Eccrine glandEccrine gland Over entire bodyOver entire body None in nail beds, lips, eardrumNone in nail beds, lips, eardrum Secrete perspirationSecrete perspiration Emotions cause the palms, fingers and soles Emotions cause the palms, fingers and soles

to respond more.to respond more. Keeps the body from over heatingKeeps the body from over heating

Sudoriferous (Sweat) GlandSudoriferous (Sweat) Gland Apocrine or odiferous glandApocrine or odiferous gland

In armpits, dark region around nipples, In armpits, dark region around nipples, othersothers

Female breast contain these glands that Female breast contain these glands that adapted to secrete and release milk.adapted to secrete and release milk.

Become active at pubertyBecome active at puberty Respond to stress and has an odor.Respond to stress and has an odor. Contains a specific human pheromoneContains a specific human pheromone Glands in the ear canals that produce wax.Glands in the ear canals that produce wax.

Sebaceous (Oil) GlandsSebaceous (Oil) Glands

LubricationLubricationProtection against bacteria & Protection against bacteria &

fungifungiPermeability barrierPermeability barrierSkin softening agentSkin softening agent

ProtectionProtection Scalp hair protects & insulationsScalp hair protects & insulations Eyelashes & eyebrowsEyelashes & eyebrows Arrector pili muscleArrector pili muscle Parts are Parts are

Shaft, Shaft, RootRoot BulbBulb

Parts of the SkinParts of the Skin

When things When things go Wronggo Wrong

Blackheads & PimplesBlackheads & Pimples

WartsWarts

Ring WormRing Worm

StaphylococciStaphylococci

StaphylococciStaphylococci