Anatomy and Physiology chapter 5 Questions and Correct Answers Graded A+

Functions of skin 1.Protection of underlying tissues and organs tion of salts, water, and organic waste (glands) 3.Maintenance of body temperature (insulation & evaporation) 4.Production of melanin 5.Production of Keratin 6.Synthesis of vitamin D3 7.Storage of lipids 8.Detection of touch, pressure, pain, and temperature 9.Coordination of immune response Protective elements of skin Keratin, Lipids, Glandular Secretions, Melanin Thermoregulation Controls internal temp Vitamin D synthesis You need Vitamin D to absorb calcium Epidermis Superficial layer of skin. Avascular. 4 different cell types (Keratinocytes, Melanocytes, Langerhans cells, merkel cells) fingerprint production continuously produced in deepest layers and shed at exposed surface Keratinocytes 90% of cells. Keratin Melanocytes manufacture melanin from amino acids and tyrosine package melanin in vesicles (melanosomes) occur in stratum basale and spinosum located in bottom 2 layers 8% of cells. Melanin (Pigments and absorb uv radiation. Langerhans Cells Immune function Merkel cells Touch Layers of skin (Superficial to deep) Epidermis, Dermis Epidermal Layers (deep to superficial) Stratum Basale, Stratum spinosum, Stratum granulosum, Stratum lucidum, Stratum corneum. Stratum Basale Basal cells "stem ceclls" actively divide to replace lost cells or superficial layers highly mitotic layer Keratinocytes, Melanocytes, Langerhans cells and Merkel cells are here. Deepest layer, and mitosis occurs. Stratum Spinosum "spiny layer" 8-10 layers Dendritic cells - defend against pathogens and superficial cancers. Keratinocytes and Langerhans cells are here. Production of melanocytes here. Stratum granulosum "grainy layer" 3-5 layers living cells have stopped dividing and started making keratin and keratohyalin Makes skin hard Lamellar granules, apoptosis occurs here. Stratum lucidum "clear layer" Present only in thick skin Stratum corneum "horn" outermost productive layer 15-30 layers keratinized cells all dead cells attached with desmosomes 2wks before shedding Keratin, and continuously shed (Outermost layer) Dermis Deep layer, Beneath epidermis, Vascular, LAyers: Papillary and reticular