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17 Cards in this Set
- Front
- Back
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What are the 3 layers that skin consists of?
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Epidermis
Dermis Hypodermis (subcutis) |
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Where do each of the skin layers originate from?
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Epidermis - ectoderm
Dermis and hypodermis - mesoderm |
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What are 10 functions of skin?
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Enclosing barrier - for internal organs
Water and nutrient barrier Environmental barrier (chemical, microbial and physical) Provides shape and form Produces keratinised structures Produces sebum - antimicrobial Camouflage Temperature regulation Sensory perception Vitamin D |
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Which type of glands are found on the digital pads of carnivores?
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Merocrine
(apocrine found all over body) |
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What are the 3 types of hair?
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Guard hair
Wool hair - soft undercoat, thin, shorter, more numerous than guard hairs, lack medulla Tactile hair - thicker, protrude beyond guard hairs, form whiskers |
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Name labels A to F
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A- stratum corneum
B- stratum lucidum C- stratum granulosum D- stratum spinosum E- stratum basale F- dermis |
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Describe the stratum corneum
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Made up of dead keratinocytes, continually replaced, cells surrounded by lipids in interC space. Contains keratin fibres in cells, keratin lies in keratohyalin
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Describe the stratum granulosum
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Cells have flattened, they produce keratohyalin, contain keratohyalin granules
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Describe the stratum spinosum
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Enlarged, keratin fibres produced, lipid secreted into intercellular space.
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Describe the stratum basale
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Single layer of cells, contains keratinocytes and melanocytes
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What is the structure at the end of a hair follicle called?
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Papilla - connective tissue and capillary loop
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What is a hair made up of?
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Medulla, cortex and cuticle
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What surrounds the hair?
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Internal and external root sheath
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What happens in the 3 stages of hair growth?
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Anagen - hair produced by mitosis in hair bulb, cells undergo keratinisation
Catagen - hair bulb is constricted, CT sheath thickens and pushes club hair externally Telogen - dermal papilla separates, a secondary hair germ forms |
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What is the function of a Merkel cell?
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Touch receptor
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What are Langerhans cells?
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Dendritic cells, antigen-presenting cells, prominant in s.spinosum
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What are functions of hair?
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Camouflage
Warmth Communication to other animals Protection (hedgehog) Detection of dirt (eyelashes) |
