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29 Cards in this Set
- Front
- Back
Define Integument
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-the protective, pliable covering over the surface of the body
-The skin is the largest organ in the body |
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Define Integumentary System
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-a body system consisting of the integument and any accessory skin structures, such as nails, hair, and glands
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Functions of the Integument:
protection? |
-protection from infectious agents
-the integument acts as a physical barrier and has a slightly acidic pH which acts as an antiseptic layer, preventing organisms from entering the body |
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Functions of the Integument:
perception? |
-perception on the environment
-neural receptors of the skin |
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Functions of the Integument:
prevention? |
-prevention of drying out and absorption of water (keratin)
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Functions of the Integument:
regulation? |
-a coordinated activity of nerve endings, blood vessels, and sweat glands
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Functions of the Integument:
secretion? |
-production of sebum by the sebaceous glands
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Functions of the Integument:
excretion? |
-release of urea and NaCl by the sweat glands
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Functions of the Integument:
production of? |
-production of Vitamin D
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Functions of the Integument:
emotions |
-allows for emotions
-ex: blushing, smiling, frowning |
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Epidermis
How is the epidermis affected by tanning? |
-UV light stimulates melanocytes to produce melanin which is then picked up (phagocytized) by more superficial cells of the epidermis
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Epidermis
What are freckles? |
-localized collections of melanin
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Epidermis Cell Types
Keratinocyte |
-primary cell type of the epidermis (arise from mitotically active cells called basal cells)
-generates keratin |
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Epidermis Cell Type
Melanocyte |
-a cell of the germainativism layer of the epidermis
-produces melanin, a black pigment of the skin |
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Epidermis Cell Type
Langerhans cells |
-Langerhans cells are Nonpigmented granular dendrocytes
-they arise in bone marrow and reside in the spinosum layer of the epidermis -sensitive to UV radiation -present antigens to T cells to assist the immune response |
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Epidermis Cell Type
Granstein cells |
-Granstein cells are Nonpigmented granular dendrocytes
-resistant to UV radiation -interact with suppressor T cells to assist the immune response |
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Epidermis Cell Type
Merkel cells |
-mechanoreceptors of the germinativum layer of the epidermis (found in areas where hair is lacking; release chemicals that stimulate sensory nerve endings)
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Layers of the Epidermis
stratum germinativum or stratum basale |
-the inner, mitoically active cell layer of columnar to cuboid shapes cells
-the cells contain melanin produced by melanocytes -cells are joined by desmosomes |
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Layers of the Epidermis
stratum spinosum |
-a region several cell layers thick; deep cells are polyhedral, superficial cells are flat
-cells are characterized by cytoplasmic spines which meet from other cells at a desmosome (spines maitain cohesion between cells and thus, resist abrasion) |
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Layers of the Epidermis
stratum granulosum |
-granulosum=granular
-a region of 3-5 layers of flattened cells whose cytoplasm contains keratohyalin granules; keratohyalin is a protein which will form eleidin -nuclei are degrading; outermost cells are dead -extruded materials from these cells offer a barrier to foreign materials and water |
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Epidermis Description:
What is carotene? |
-carotene is a yellow pigment which can be convertd to Vitamin A
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Epidermis Description:
What about Albinos? |
-Albinos have melanocytes but lack the enzyme neccessary to convert tryosin to melanin.
*Asians have an abudance of carotene |
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Epidermis Description:
layer? |
-outer, thinner layer of skin
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Epidermis Description:
kind of epithelium? |
-consists of stratified squamous epithelium
-a derivative of the ectoderm |
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Epidermis Description:
colored? |
-the epidermis is colored because of the presence of melanin, carotene, and blood
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Epidermis Description:
What is melanin? |
-produced by melanocytes of the epidermis; specifically an enzyme called tyrosinase coverts tryosine to melanin
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Layers of the Epidermis:
stratum lucidum |
-lucid=clear
-a clear, homogenous layer composed of flattened, drying cells which contain eleidin -this layer is 3-5 cells thick -cell boundaries and nuclei are rarely seen |
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Layers of the Epidermis:
stratum corneum |
-cornu=horn
-the outermost epidermal layer, consisting of flat, scale-like, dead, cornified cells whose cytoplasm contains the fibrous protein keratin. -this surface is water-resistant, not waterproof. Interstital fluid slowly penetrates the surface to be evaporated into the air. This is different from lost by perspiration. -cells of the corneum are held together by modified desmosomes -the stratum corneum forms a barrier against light, heat, bacteria, and chemicals -it takes about 2 weeks to 1 month for cells to arise by mitosis in the germanativum layer, push to the surface of the skin, and slough off |
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Layers of the Epidermis:
What is keratin? |
-Keratin arises from eleidin and waterproofs the skin
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