Review Topics Listed below are some of the key topics discussed in class This is not meant to be a comprehensive review of lessons 7 12 for that you should go over your notes RED points on study guide Blue extra info that seems important Green red info given in lecture Make sure to go over Mastering A P homework assignments there were many questions pulled straight from there Lesson 7 What are the components of the integumentary system What are the main functions of the skin Components of the Integumetary system o Cutaneous Membrane skin Consists of two components Outer epidermis o Superficial epithelium Inner dermis o Connective tissues o Accessory Structures Originate in the dermis Include hairs nails multicellular exocrine glands Five Main Functions of the Skin o 1 Protection of underlying tissues and organs o 2 Excretion of salts water and organic wastes glands o 3 Maintenance of body temperature insulation and evaporation o 4 Production of melanin keratin vitamin D3 and storage of lipids o 5 Detection of touch pressure pain and temperature Which cell types are found in the epidermis Which cell types are found in the different layers of the epidermis Composed of stratified squamous epithelium o Avascular dominated by keratinocytes most abundant type of epithelial cells Contain large amounts of keratin protein Cell Types in the Different Layers of the Epidermis inferior to superior o Stratum basale Basal cells or germinative cells Merkel cells Respond to touch trigger nervous system Found in hairless skin Melanocytes Contain the pigment melanin Scattered throughout layer o Stratum spinosum Contain dendritic Langerhans cells active in immune response o Stratum granulosom Cells Produce protein fibers dehydrate and die create tightly interlocked layer of keratin surrounded by keratohyalin o Stratum lucidum only in thick skin Cells are flattened densely packed with keratin devoid of organelles o Stratum corneum Exposed surfaces undergo cornification keratinization Formation of protective superficial layers or cells filled with keratin o Cells are dead and linked together by desmosomes o water resistant not water proof o shed and replaced every 2 weeks How many major layers are there in thick skin How about in thin skin What are the characteristics of each of these layers Thick Skin 5 layers of keratinocytes covers palms and soles o Stratum basale lowest layer Attached to basement membrane by hemidesmosomes Forms epidermal ridges basis for fingerprints Ridge patterns on skin increases surface area and friction ensuring a secure grip Has dermal papillae tiny mounds Increase the area of basement membrane Strengthen attachment between epidermis and dermis o Stratum spinosum the spiny layer 8 10 layers of keratinocytes bound by desmosomes Produced by division of stratum basale Cells shrink until cytoskeleton stick out Continue to divide increasing thickness of epithelium o Stratum granulosum the grainy layer Stops dividing and starts producing Keratin o A tough fibrous protein o Makes up hair and nails which are accessory structures Keratohyalin o Dense granules o Cross link keratin fibers o Stratum lucidum The clear layer FOUND ONLY IN THICK SKIN Covers stratum granulosum o Stratum corneum the horn layer Exposed surface of skin Takes 15 30 days for a cell to move from stratum basale to stratum corneum Thin Skin 4 layers of keratinocytes characteristics of layers are the same as above notice stratum lucidum is missing here covers most of body o Stratum basale o Stratum spinosum o Stratum granulosum o Stratum corneum Why are the dermal papillae important Where are they located How are they related to the epidermal ridges Dermal papillae o Important Increase the area of basement membrane and strengthen attachment between epidermis and dermis o Located Stratum basale o Related to epidermal ridges both increase surface area and strength of attachment What is the difference between insensible perspiration and sensible perspiration Insensible Perspiration o Interstitial fluid lost by evaporation through the stratum corneum Sensible Perspiration o Fluid excreted by sweat glands Dehydration results from o Damage to stratum corneum burns and blisters Affects Insensible perspiration o Immersion in HYPERtonic solution osmosis Hydration can occur through osmosis also o Immersion in HYPOtonic solution Swelling of epithelial cells Which conditions can affect the color of skin Which pigments can affect skin color Why are melanocytes important in preventing cancer Condition that affect the color of skin o Blood circulation red blood cells can affect skin color i e blushing Capillaries carrying blood alter skin color Oxygenated red blood o Vessels dilate from hear skin reddens o Flow decrease skin pales Cyanosis bluish skin tint Caused by severe reduction in blood flow or oxygenation o Illnesses that affect skin color Jaundice Pituitary tumor Buildup of bile produced by liver yellow color Excess MSH melanocyte stimulating hormone Extremely bronze tan Addison s Disease A disease of the pituitary gland releases more ACTH adrenocorticotropic hormone similar effect on skin color as MSH Skin darkening Loss of melanocytes probably caused by autoimmune reaction by Vitiligo antibodies Loss of color Pigments that affect skin color o Carotene o Melanin Orange yellow pigment Found in orange vegetables EX Carrots squashes if consume too much can turn skin orange Accumulates in epidermal cells and fatty tissues of the dermis Can be converted to Vitamin A for maintenance of epithelia and photoreceptor function lack causes night blindness nyctalopia Yellow brown or black pigment Produced by melanocytes in stratum basale from the amino acid tyrosine Stored in transport vesciles melanosomes Transferred to keratinocytes Albino have melanocytes but can t produce melanin Skin color depends on melanin production not number of melanocytes Importance of melanocytes in preventing cancer o Protects skin from sun damage Ultraviolet UV raditions Causes DNA mutations and burns that lead to cancer and wrinkles Melanosomes of keratinocytes concentrate around nucleus to protect DNA Why is vitamin D associated with the integumentary system Which organ system s does it play a role in Epidermal cells produce vitamin D3 in the presence of UV radiation o Liver and kidneys convert it into calcitriol Aids absorption of calcium and phosphorous Insufficient vitamin D3 can cause rickets bending of weak bones under body weight What are the
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