5Skin (Integument)Slide 3EpidermisSlide 5Layers of the Epidermis: Stratum Basale (Basal Layer)Layers of the Epidermis: Stratum Spinosum (Prickly Layer)Layers of the Epidermis: Stratum Granulosum (Granular Layer)Layers of the Epidermis: Stratum Lucidum (Clear Layer)Layers of the Epidermis: Stratum Corneum (Horny Layer)Slide 11DermisSlide 13Layers of the Dermis: Papillary LayerLayers of the Dermis: Reticular LayerSkin Markings: Friction RidgesSlide 17Skin Markings: Cleavage LinesSlide 19Skin ColorSlide 21Appendages of the SkinSweat GlandsSlide 24Slide 25Sebaceous (Oil) GlandsSlide 27HairSlide 29Slide 30Slide 31Hair FollicleSlide 33Slide 34Slide 35Types of HairSlide 37Hair Thinning and BaldnessStructure of a NailSlide 40Functions of the Integumentary SystemSlide 42Slide 43Slide 44Skin CancerSlide 46Basal Cell CarcinomaSlide 48Squamous Cell CarcinomaSlide 50MelanomaSlide 52Slide 53BurnsRule of NinesSlide 56Partial-Thickness BurnsSlide 58Full-Thickness BurnsSlide 60Severity of BurnsDevelopmental Aspects: FetalDevelopmental Aspects: Adolescent to AdultDevelopmental Aspects: Old AgeSlide 65Skin-Burns: Study GuideSkin-Healing of Wounds: Study GuidePowerPoint® Lecture Slides prepared by Janice Meeking, Mount Royal CollegeC H A P T E RCopyright © 2010 Pearson Education, Inc.5 The Integumentary SystemCopyright © 2010 Pearson Education, Inc.Skin (Integument)•Consists of three major regions1. Epidermis—superficial region2. Dermis—middle region3. Hypodermis (superficial fascia)—deepest region•Subcutaneous layer deep to skin (not technically part of skin)•Mostly adipose tissueCopyright © 2010 Pearson Education, Inc.Figure 5.1EpidermisHair shaftDermisReticularlayerPapillarylayerHypodermis(superficial fascia)Dermal papillaePoreSubpapillaryvascular plexusAppendagesof skin • Eccrine sweat gland• Arrector pili muscle• Sebaceous (oil) gland• Hair follicle• Hair rootNervous structures• Sensory nerve fiber• Pacinian corpuscle• Hair follicle receptor (root hair plexus)Cutaneous vascularplexusAdipose tissueCopyright © 2010 Pearson Education, Inc.Epidermis•Keratinized stratified squamous epithelium •Cells of epidermis•Keratinocytes—produce fibrous protein keratin•Melanocytes•10–25% of cells in lower epidermis•Produce pigment melanin•Epidermal dendritic (Langerhans) cells—macrophages that help activate immune system •Tactile (Merkel) cells—touch receptorsCopyright © 2010 Pearson Education, Inc.Figure 5.2aDermisStratum corneumMost superficial layer; 20–30 layers of deadcells represented only by flat membranoussacs filled with keratin. Glycolipids inextracellular space.Stratum granulosumThree to five layers of flattened cells,organelles deteriorating; cytoplasm full oflamellated granules (release lipids) andkeratohyaline granules.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 epidermaldendritic cells.(a)Copyright © 2010 Pearson Education, Inc.Layers of the Epidermis: Stratum Basale (Basal Layer)•Deepest epidermal layer firmly attached to the dermis•Single row of stem cells•Also called stratum germinativum: cells undergo rapid division•Journey from basal layer to surface•Takes 25–45 daysCopyright © 2010 Pearson Education, Inc.Layers of the Epidermis: Stratum Spinosum (Prickly Layer)•Cells contain a weblike system of intermediate prekeratin filaments attached to desmosomes•Abundant melanin granules and dendritic cellsCopyright © 2010 Pearson Education, Inc.Layers of the Epidermis: Stratum Granulosum (Granular Layer)•Thin; three to five cell layers in which the cells flatten•Keratohyaline and lamellated granules accumulateCopyright © 2010 Pearson Education, Inc.Layers of the Epidermis: Stratum Lucidum (Clear Layer)•In thick skin•Thin, transparent band superficial to the stratum granulosum•A few rows of flat, dead keratinocytesCopyright © 2010 Pearson Education, Inc.Layers of the Epidermis: Stratum Corneum (Horny Layer)•20–30 rows of dead, flat, keratinized membranous sacs•Three-quarters of the epidermal thickness•Functions•Protects from abrasion and penetration•Waterproofs•Barrier against biological, chemical, and physical assaultsCopyright © 2010 Pearson Education, Inc.Figure 5.2bMelanocyteMelanin granuleTactile(Merkel) cell Sensorynerve endingEpidermaldendritic cellDermisKeratinocytesStratum corneumMost superficial layer; 20–30 layers of dead cells represented only by flat membranous sacs filled with keratin. Glycolipids in extracellular space.Stratum granulosumThree to five layers of flattened cells, organelles deteriorating; cytoplasm full of lamellated granules (release lipids) and keratohyaline granules.Stratum spinosumSeveral layers of keratinocytes unified by desmosomes. Cells contain thick bundles of intermediate filaments made of pre-keratin.Stratum basaleDeepest epidermal layer; one row of actively mitotic stem cells; some newly formed cells become part of the more superficial layers. See occasional melanocytes and epidermal dendritic cells. Desmosomes(b)Copyright © 2010 Pearson Education, Inc.Dermis•Strong, flexible connective tissue•Cells include fibroblasts, macrophages, and occasionally mast cells and white blood cells•Two layers: •Papillary•ReticularCopyright © 2010 Pearson Education, Inc.Figure 5.1EpidermisHair shaftDermisReticularlayerPapillarylayerHypodermis(superficial fascia)Dermal papillaePoreSubpapillaryvascular plexusAppendagesof skin • Eccrine sweat gland• Arrector pili muscle• Sebaceous (oil) gland• Hair follicle• Hair rootNervous structures• Sensory nerve fiber• Pacinian corpuscle• Hair follicle receptor (root hair plexus)Cutaneous vascularplexusAdipose tissueCopyright © 2010 Pearson Education, Inc.Layers of the Dermis: Papillary Layer•Papillary layer•Areolar connective tissue with collagen and elastic fibers and blood vessels•Dermal papillae contain: •Capillary loops •Meissner’s corpuscles•Free nerve endingsCopyright © 2010 Pearson Education, Inc.Layers of the Dermis: Reticular Layer•Reticular layer•~80% of the thickness of dermis•Collagen fibers provide strength and resiliency •Elastic fibers provide stretch-recoil propertiesCopyright © 2010 Pearson