123-2316_IMG The structure and functions of the skin Skin of an adult §Surface 1,5 – 2m² §Weight 18 – 20 kg § 15-19% of total weight § §Epidermis and dermis mean thickness 2mm §(0,5 kg and 3,5 kg) §Subcutaneous tissue 8-25mm 152-5282_IMG Epidermis Dermis Subcutaneous fat Blood and lymphatic vessels Hair follicle unit Sweat glands Nerves Connective tissue vyzravanimela www. muni.cz/atlases 123-2320_IMG 152-5291_IMG Keratinocyte and keratinization Horny layer 12 days Granular layer- keratinohyaline granules 2 days Stratum spinosum – 6 days Basal cell layer - 8-10 days Total 28-30 days 152-5284_IMG Horny layer - epidermal barrier TEWL - transepidermal water loss Disorders - hyperkeratosis proliferation x retention - parakeratosis - dyskeratosis Související obrázek Související obrázek Výsledek obrázku pro transepidermal water loss 152-5285_IMG Epidermal melanin unit 1/36 Tyrosine – Dopa – Dopaquinone – Eumelanin, phaeomelanin Tyrosinase 152-5287_IMG Dermo epidermal junction -basement membrane zone hemidesmosome lamina lucida lamina densa collagen IV collagen VII 152-5288_IMG Dermis – cells + extracellular matrix - fibres, ground substance Výsledek obrázku pro collagen I dermis Výsledek obrázku pro ground substance Some functions of dermal resident cells §Fibroblast synthesis of collagen, reticulin, elastin, fibronectin, glycosaminoglycans § §Mononuclear phagocyte phagocytose (bacteria), cytokine secretion §Lymphocyte – immunosurveillance §Mast cell – release of mediators (histamine, heparin, prostaglandins, leukotriens, tryptase etc 152-5289_IMG Pilosebaceous unit Hair cycle anagen – katagen – telogen 1000 – 10 – 100 days Výsledek obrázku pro hair cycle phases 152-5292_IMG 152-5290_IMG Nerves Nerve endings Merkel cells Corpuscles Temperature Pressure Vibration Touch Itch Pain Výsledek obrázku pro itch nerves The function of the skin §1. Protection against §Chemicals § §physical factors – UV, cold, heat, mechanical injury § §infections § §antigens §Horny layer, (pH 5,5) § §Melanocytes, urocanic acid § §Antimicrobial peptides § §Langerhans cells § Skin microbioma The function of the skin §2.Preservation of balanced internal environment §Loss of water, electrolytes, macromolecules §3. Temperature regulation § §4. Shock absorber § §5. Sensation § §6. Energy and water reserve § §Horny layer § § § §Blood vessels, eccrine sweat glands §Dermis, subcutaneous fat § §Nerves § §Subcutaneous fat, dermis § Thermoregulation Výsledek obrázku pro temperature regulation skin The function of the skin § §7. Vitamin D synthesis § §8. Own metabolic function § §9. Immunological § §10. Detoxicant § §Keratinocytes § §Keratinocytes §Fibroblasts § Výsledek obrázku pro transepidermal water loss The function of the skin §8.Protection and fight § §9. Psychosocial function § §10. Body odour §Nails, hair § §Cosmetic quality, lips, hair § §Apocrine sweat glands Výsledek obrázku pro fight or flight hair animal Arnold-Schwarzenegger Související obrázek