INTEGUMENTINTEGUMENT

Surface AnatomySurface Anatomy

PalpationPalpationBony landmarksBony landmarksDermatomesDermatomes

Neural assessmentNeural assessment

Integument HistologyIntegument Histology

Epidermis:Epidermis:Stratified squamous epitheliumStratified squamous epithelium

Resting on:Resting on:Basement membraneBasement membrane

Resting on:Resting on:Dermis:Dermis:

Dense irregular connective tissueDense irregular connective tissue

EpidermisEpidermis

The epidermis is a stratified squamous The epidermis is a stratified squamous epithelium.epithelium.

It is made up of many layers of cells.It is made up of many layers of cells.The stratum germinativum is the deepest The stratum germinativum is the deepest

layer:layer:Area of high mitotic activity.Area of high mitotic activity.

EpidermisEpidermis

The stratum corneum is the most The stratum corneum is the most superficial layer:superficial layer:

The cells in this layer are dead and The cells in this layer are dead and keratinized.keratinized.

Between the stratum germinativum and Between the stratum germinativum and the stratum corneum are several the stratum corneum are several transitional layers represented by cells transitional layers represented by cells from the stratum germinativum that are from the stratum germinativum that are transforming into dead, keratinized cells.transforming into dead, keratinized cells.

EpidermisEpidermis

The epidermis is innervated.The epidermis is innervated.The epidermis is avascular.The epidermis is avascular.

DermisDermis

The dermis is the deepest region of the The dermis is the deepest region of the integument.integument.

The dermis is classified as dense irregular The dermis is classified as dense irregular connective tissueconnective tissue

The dermis has an abundance of collagen The dermis has an abundance of collagen fibersfibers

There may also be some elastic fibers:There may also be some elastic fibers:Decrease with age.Decrease with age.

DermisDermis

The dermis is vascularized.The dermis is vascularized.Refer to Figure 1 in your course packet.Refer to Figure 1 in your course packet.

Thick Skin vs. Thin SkinThick Skin vs. Thin Skin

Classification into thin and thick skin Classification into thin and thick skin depends on the structure of the epidermis.depends on the structure of the epidermis.

Layers of epidermis are well-formed in Layers of epidermis are well-formed in thick skin.thick skin.

Layers of epidermis are not as well-formed Layers of epidermis are not as well-formed or thick in thin skin.or thick in thin skin.

Thick SkinThick Skin

Thick skin is found only on the palms of Thick skin is found only on the palms of the hands and the soles of the feet.the hands and the soles of the feet.

The epidermis of thick skin is 0.4 – 0.6 mm The epidermis of thick skin is 0.4 – 0.6 mm thickthick

Thick skin has no hair follicles.Thick skin has no hair follicles.

Thin SkinThin Skin

Thin skin is found over the rest of the Thin skin is found over the rest of the body.body.

The epidermis of thin skin is 0.075 – 0.150 The epidermis of thin skin is 0.075 – 0.150 mm thick.mm thick.

Total skin thickness is 0.5 – 3 mm thick.Total skin thickness is 0.5 – 3 mm thick.

Skin ThicknessSkin Thickness

Thickest skin found on back (= thin skin)Thickest skin found on back (= thin skin)Thinnest skin found on eyelids (= thin skin)Thinnest skin found on eyelids (= thin skin)Thicker on extensor surfaces than flexor Thicker on extensor surfaces than flexor

surfaces.surfaces.

Superficial Fascia: SynonymsSuperficial Fascia: Synonyms

Subcutaneous fasciaSubcutaneous fasciaSuperficial fasciaSuperficial fasciaHypodermisHypodermisSubQ SubQ

Superficial FasciaSuperficial Fascia

Consists of loose bundles of collagen and Consists of loose bundles of collagen and elastic fibers with variably sized elastic fibers with variably sized aggregations of lipocytes (fat cells)aggregations of lipocytes (fat cells)

May be loosely or tightly attachedMay be loosely or tightly attachedSupports cutaneous nerves and blood Supports cutaneous nerves and blood

vesselsvessels

Deep FasciaDeep Fascia

Synonyms:Synonyms:Membranous fasciaMembranous fascia

Investing fasciaInvesting fasciaUsually several thin layers of tough Usually several thin layers of tough

collagen materialcollagen materialTightly adherent to muscles, bones, Tightly adherent to muscles, bones,

tendons, etc.tendons, etc.

Cutaneous DerivativesCutaneous Derivatives

Glands.Glands.Hairs.Hairs.Nails.Nails.

GlandsGlands

Glands are epithelial structuresGlands are epithelial structuresGlands are classified according to the Glands are classified according to the

presence or absence of a secretory duct:presence or absence of a secretory duct:

ExocrineExocrine

Endocrine Endocrine

Epidermal GlandsEpidermal Glands

Sudoriferous glandsSudoriferous glandsSebaceous glandsSebaceous glandsCeruminous glandsCeruminous glandsMammary glandsMammary glands

Sudoriferous GlandsSudoriferous Glands

Are long, simple, tubular glands.Are long, simple, tubular glands.

Their method of secretion is merocrine .Their method of secretion is merocrine .

Sebaceous GlandsSebaceous Glands

Are holocrine .Are holocrine .

Sebaceous glands are associated with Sebaceous glands are associated with hair follicles.hair follicles.

Ceruminous GlandsCeruminous Glands

Are located in the external auditory canal.Are located in the external auditory canal.

Secrete ear wax. Secrete ear wax.

Mammary GlandsMammary Glands

Are modified sweat glandsAre modified sweat glands

Method of secretion is apocrine Method of secretion is apocrine

HairsHairs

Hairs develop during 3Hairs develop during 3rdrd month of month of gestation.gestation.

The earliest fine embryonic hair = lanugo.The earliest fine embryonic hair = lanugo.

Lanugo is Shed before birth except around Lanugo is Shed before birth except around eyebrows, scalp, and eyelids.eyebrows, scalp, and eyelids.

HairsHairs

A new downy coat of hair appears a few A new downy coat of hair appears a few months after birth.months after birth.

This new coat is called vellus.This new coat is called vellus.Vellus is converted to terminal hair at Vellus is converted to terminal hair at

puberty:puberty:Vellus represents 95% of the hair Vellus represents 95% of the hair

coverage coverage in males.in males.Vellus represents 35% of the hair Vellus represents 35% of the hair

coverage coverage in females.in females.

Parts of a HairParts of a Hair

Shaft:Shaft:Made up of dead cornified epidermal cells.Made up of dead cornified epidermal cells.

Follicle:Follicle:Derived from both epidermis and dermis.Derived from both epidermis and dermis.

Dermal papilla with matrix.Dermal papilla with matrix.

Parts of a HairParts of a Hair

Arrector pili muscle.Arrector pili muscle.Sebaceous glands.Sebaceous glands.Hair bulb and connective tissue papilla.Hair bulb and connective tissue papilla.

Hair GrowthHair Growth

Anlagen Anlagen Active growth:Active growth:

Scalp hair = 2-3 yearsScalp hair = 2-3 years

Eyebrow hair = 3-4 monthsEyebrow hair = 3-4 months

Hair Function and LocationHair Function and Location

Hair follicles are innervated, and hairs Hair follicles are innervated, and hairs serve as sensory receptors.serve as sensory receptors.

Hairs are found everywhere except palms, Hairs are found everywhere except palms, soles, dorsal distal phalanges, anal and soles, dorsal distal phalanges, anal and urogenital aperturesurogenital apertures

NailsNails

Ungis:Ungis:

Modified stratum corneumModified stratum corneum

Flattened Flattened

Avascular and not innervatedAvascular and not innervated

Travels over a nail bed guided by lateral Travels over a nail bed guided by lateral nail nail groovesgrooves

Matrix:Matrix:Stratum germinativum produces ungisStratum germinativum produces ungis

Subungis Subungis

MelanocytesMelanocytes

Found in deep layers of epidermisFound in deep layers of epidermisDerived from nervous system componentsDerived from nervous system componentsForm:Form:

Melanosomes:Melanosomes: Passed off to keratinocytes (cells of Passed off to keratinocytes (cells of epidermis).epidermis).

Phagocytized by keratinocytes.Phagocytized by keratinocytes.

MelanocytesMelanocytes

All individuals produce same number of All individuals produce same number of melanosomes.melanosomes.

Skin color depends on number of Skin color depends on number of remaining melanosomes.remaining melanosomes.

Langer’s LinesLanger’s Lines

Represent tension lines created by Represent tension lines created by orientation of collagen fibers in the dermis orientation of collagen fibers in the dermis of the skin.of the skin.

Used by surgeons as guides for incisions:Used by surgeons as guides for incisions:Incisions normally made parallel to Incisions normally made parallel to

Langer’s Langer’s lineslines

DermatomesDermatomes

Specific region of skin innervated by a Specific region of skin innervated by a specific spinal cord level.specific spinal cord level.

Refer in syllabus to figure 3Refer in syllabus to figure 3