© 2013 Pearson Education, Inc. Chapter Opener 5. © 2013 Pearson Education, Inc. Figure 5.1 Skin structure. Hair shaft Epidermis Papillary layer Dermis

© 2013 Pearson Education, Inc.

Chapter Opener 5


Figure 5.1 Skin structure.

Hair shaft

Epidermis

Papillarylayer

Dermis Reticularlayer

Hypodermis(subcutaneoustissue; not partof skin)

Dermal papillae

Subpapillaryplexus

Sweat pore

Cutaneous plexus

Adipose tissue

Nervous structuresSensory nerve fiberwith free nerve endingsLamellar corpuscleHair follicle receptor(root hair plexus)

Appendages ofskinEccrine sweat glandArrector pili muscle

Sebaceous (oil)glandHair follicleHair root


Figure 5.2 The main structural features of the skin epidermis.

Stratum spinosumSeveral layers of keratinocytes unified bydesmosomes. Cells contain thick bundles ofintermediate filaments made of pre-keratin.

Stratum basaleDeepest epidermal layer; one row of activelymitotic stem cells; some newly formed cellsbecome part of the more superficial layers.See occasional melanocytes and dendriticcells.

Melanocyte Dendriticcell

Keratinocytes

Dermis

Stratum corneumMost superficial layer; 20–30 layers of deadcells, essentially flat membranous sacsfilled with keratin. Glycolipids inextracellular space.

Dermis

Melaningranule

Sensorynerveending

Tactile(Merkel)cell

Desmosomes

Stratum granulosumTypically five layers of flattened cells, organellesdeteriorating; cytoplasm full of lamellar granules(release lipids) and keratohyaline granules.


Figure 5.2a The main structural features of the skin epidermis.

Dermis

Stratum spinosumSeveral layers of keratinocytes unified by desmosomes.Cells contain thick bundles of intermediate filaments made ofpre-keratin.

Stratum basaleDeepest epidermal layer; one row of actively mitotic stemcells; some newly formed cells become part of the moresuperficial layers. See occasional melanocytes and dendriticcells.

Stratum granulosumTypically five layers of flattened cells, organelles deteriorating;cytoplasm full of lamellar granules (release lipids) andkeratohyaline granules.

Stratum corneumMost superficial layer; 20–30 layers of dead cells, essentiallyflat membranous sacs filled with keratin. Glycolipids inextracellular space.


Figure 5.2b The main structural features of the skin epidermis.

Stratum spinosumSeveral layers of keratinocytes unified by desmosomes.Cells contain thick bundles of intermediate filamentsmade of pre-keratin.

Stratum basaleDeepest epidermal layer; one row of activelymitotic stem cells; some newly formed cellsbecome part of the more superficial layers.See occasional melanocytes and dendriticcells.

Melanocyte

Dendriticcell

Keratinocytes

Stratum corneumMost superficial layer; 20–30 layers of dead cells,essentially flat membranous sacs filled with keratin.Glycolipids in extracellular space.

Dermis

Melaningranule

Sensorynerveending

Tactile(Merkel) cell

Desmosomes

Stratum granulosumTypically five layers of flattened cells, organellesdeteriorating; cytoplasm full of lamellar granules(release lipids) and keratohyaline granules.


Figure 5.3 Light micrograph of the dermis identifying the papillary layer composed of areolar connective tissue and the reticular layer of dense irregular connective tissue (110x).

Epidermis

Papillarylayer

Dermis

Reticularlayer


Figure 5.4 Dermal modifications result in characteristic skin markings.

Openings ofsweat gland ducts

Frictionridges

Friction ridges offingertip (SEM 12x)

Cleavage lines in thereticular dermis

Flexure lines of thehand

Flexure lineson the palm

Flexure lineson digit


Figure 5.4a Dermal modifications result in characteristic skin markings.

Openings ofsweat gland ducts

Frictionridges

Friction ridges offingertip (SEM 12x)


Figure 5.4b Dermal modifications result in characteristic skin markings.

Cleavage lines in thereticular dermis


Figure 5.4c Dermal modifications result in characteristic skin markings.

Flexure lines of thehand

Flexure lineson the palm

Flexure lineson digit


Figure 5.5 Skin appendages: Structure of a hair and hair follicle.

Follicle wall

Peripheralconnective tissue(fibrous) sheath

Glassy membrane

Epithelial root sheathExternal root sheathInternal root sheath

HairCuticle

Cortex

Medulla

Photomicrograph of a cross section of ahair and hair follicle (100x)

Diagram of a cross section of a hair within its follicle

Hair shaft•

•

•

Follicle wall


Glassy membrane


Hair rootCuticle

Cortex

Medulla

Hair matrix

Hair papilla

Melanocyte

Subcutaneousadipose tissue

Photomicrograph of longitudinal viewof the hair bulb in the follicle (150x)

Diagram of a longitudinal view of the expanded hairbulb of the follicle, which encloses the matrix

ArrectorpiliSebaceousgland

Hair root

Hair bulb


Follicle wall


Glassy membrane


Hair

•

Cuticle

Cortex

Medulla

Diagram of a cross section of a hair within its follicle

Hair shaft

Arrectorpili

Hair root

Hair bulb

•

•

••

•

••

Sebaceousgland

Figure 5.5a Skin appendages: Structure of a hair and hair follicle.


Follicle wall


Glassy membrane


HairCuticle

Cortex

Medulla

••

•

•

•

•••

Photomicrograph of a cross section of ahair and hair follicle (100x)

Figure 5.5b Skin appendages: Structure of a hair and hair follicle.


Figure 5.5c Skin appendages: Structure of a hair and hair follicle.

Follicle wall


Glassy membrane


Hair rootCuticle

Cortex

Medulla

Hair matrix

Hair papilla

Melanocyte


Diagram of a longitudinal view of the expanded hairbulb of the follicle, which encloses the matrix

Hair shaft

ArrectorpiliSebaceousgland

Hair root

Hair bulb

•

••••

•••


Follicle wall


Glassy membrane

Hair rootCuticle

Cortex

Medulla

Hair matrix

Hair papilla


•


•

••

•

•••

Photomicrograph of longitudinal viewof the hair bulb in the follicle (150x)

Figure 5.5d Skin appendages: Structure of a hair and hair follicle.


Figure 5.6 Skin appendages: Structure of a nail.

Lunule Lateralnail fold

Root of nail

Nailmatrix

Proximalnail fold

Eponychium(cuticle)

Free edgeof nail

Bodyof nail

Phalanx (bone of fingertip)Nail bedHyponychium


Figure 5.7 Skin appendages: Cutaneous glands.

Duct

Eccrinegland

Dermal connectivetissue

Secretory cells

Sweatpore

Photomicrograph of asectioned eccrinegland (140x)

Photomicrograph of asectioned sebaceousgland (90x)

SebaceousglandDermal

connectivetissue

Hair inhair follicle

Sebaceousgland duct


Figure 5.7a Skin appendages: Cutaneous glands.

Dermalconnectivetissue

Hair inhair follicle

Sebaceousgland duct

Sebaceousgland

Eccrinegland

Photomicrograph of asectioned sebaceousgland (90x)

Secretory cells

Sweatpore


Figure 5.7b Skin appendages: Cutaneous glands.

Sebaceousgland

Eccrinegland

Sweatpore

Duct

Dermal connectivetissue

Secretory cells

Photomicrograph of asectioned eccrinegland (140x)


Figure 5.8 Photographs of skin cancers.

Basal cell carcinoma Squamous cellcarcinoma

Melanoma


Totals

Anterior and posteriorhead and neck, 9%

Anterior and posteriorupper limbs, 18%

Anterior and posteriortrunk, 36%

(Perineum, 1%)

Anterior and posteriorlower limbs, 36%

100%

41/2%

41/2% 41/2%Anteriortrunk,18%

9%9%

Figure 5.9 Estimating the extent and severity of burns using the rule of nines.


1st-degree burn

2nd-degree burn

Skin bearing partial thicknessburn (1st- and 2nd-degree burns)

Skin bearing full thicknessburn (3rd-degree burn)

3rd-degree burn

Figure 5.10 Partial thickness and full thickness burns.


System Connections 5.1

Documents

© 2013 Pearson Education, Inc. Chapter Opener 5. © 2013 Pearson Education, Inc. Figure 5.1 Skin structure. Hair shaft Epidermis Papillary layer Dermis