8ChapterSkin and Skin Appendages(Integumentary system)Department of Histology and EmbryologySchool of Medicine杨州大学YANGZHOUUNIVERSITY
Chapter 8 Skin and Skin Appendages (Integumentary system) Department of Histology and Embryology, School of Medicine
Skin?---Skin is the largestt organ of the body, itconstitutes about 16% of body weight.---its total surface area is about 1.2-2.2 m?---function:protection,reception,sensoryexcretion and thermoregulation杨州大学YANGZHOUUNIVERSITY
-Skin is the largest organ of the body, it constitutes about 16% of body weight. -its total surface area is about 1.2-2.2 m2 . -function: protection, sensory reception, excretion and thermoregulation. Skin?
1. Structure of skinthick skinthinskinStratum:corneumlucidumgranulosumephair cortexaspinosumhair cuticle---epidermisbasaleouterrootsheathsebaceous glandarrector pilisweat gland---dermiscuticlecortexmedullainternal root sheathexternal root sheathohairbulb杨州大学YANGZHOUUNIVERSITY
1. Structure of skin -epidermis -dermis
1) epidermis---keratinisedstratifiedsquamous epithelium---consist of keratinisedcellsandnon-keratinised cells杨州大学YANGZHOUUNIVERSITY
1) epidermis -keratinised stratified squamous epithelium -consist of keratinised cells and nonkeratinised cells
Dkeratinised cell:thick skin.--intherethickskiStratumare five layers. Fromcorneuucidugranulosumhair cortexbasal to surface, they0spinosumhair cuticlebasaleouterroot sheathare:sebaceous glandstratum basalearrector pilisweat glandstratum spinosumcuticlecortexmedullastratum granulosuminternal root sheathexternal root sheathhair bulbiepoestratum lucidumstratum corneum杨州大学YANGZHOUUNIVERSITY
①keratinised cell: -in thick skin, there are five layers. From basal to surface, they are: stratum basale stratum spinosum stratum granulosum stratum lucidum stratum corneum
Thick skinThin skin楊州大学YANGZHOUUNIVERSITY
Thick skin Thin skin
a. stratum basale---structure:LM:-a layer of cuboidal orlow columnar cellwith a large pale N-basophilic cytoplasmstratumbasalecells杨州大学YANGZHOUUNIVERSITY
a. stratum basale -structure: LM: -a layer of cuboidal or low columnar cell with a large pale N -basophilic cytoplasm stratum basale cells
a. Stratum basale---structure:EM:-free ribosome-keratin:filament-tonofilament-desmosomestratum-function:mitoticbasaleandactivitycellsproliferation杨州大学YANGZHOUUNIVERSITY
a. Stratum basale -structure: EM : -free ribosome -keratin: filament - tonofilament -desmosome -function: mitotic activity and proliferation stratum basale cells
stratum basalecells杨州大学YANGZHOUUNIVERSITY
stratum basale cells
b.Stratum spinosum---structure:LM: -4-10 layers polygonal cell with large roundnucleus-spinousprocesses-slightbasophiliccytoplasmEM: -tonofibrils-lamellated granules:/100-300nmmembrane-coated/contain phospholipid and steroid-intercellular bridges-Desmosome楊州大学YANGZHOUUNIVERSITY
b. Stratum spinosum -structure: LM: -4-10 layers polygonal cell with large round nucleus -spinous processes -slight basophilic cytoplasm EM: -tonofibrils -lamellated granules: /100-300nm membrane-coated /contain phospholipid and steroid -intercellular bridges- Desmosome