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40 Cards in this Set
- Front
- Back
2 distinct regions of the skin are?
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Epidermis and Dermis
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How are teh top epithelial tissues fed if only the dermis is vascularized?
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Nutrients diffuse through the tissue for the epidermis to recieve nourishment.
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The subcutaneous tissue just deep to the dermis is know as?
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Hypodermis or superficial fascia
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Half of th bodys fat is stored here. This region anchors skin to the underlying organs. It acts a shock absorber and insulator
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Hypodermis
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4 Type of cells found in the epidermis are?
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1. Keratinocytes
2. Melanocytes 3. Langerhans cells 4. Merkel cell |
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Most numerous of th skin cells. Produce keratin-waterproofs skin. Cells arise fron teh deepest part of the epidermis.
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Keratinocytes
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Located ant teh base of the epidermis. Produce the pigment melanin. same # of cells in everyone/diff activity causes diff color races.
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Melanocytes
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What is the role of melanin in the skin?
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Melanin protects the cell nucleus from the destructive effects of UV radiation.
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Arise from bone marrow and migrates to the epidermis and other areas of the body containing stratified squamous epithelial tissue.
Macrophages-assist in immune response |
Langerhans Cells
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found in small #'s at the dermal/epidermal junction. Sensory receptor
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Merkel cells
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Disc-like ending of a sensory nerve fiber
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Merkel Discs
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How many layers of:
Thin Skin? Thick Skin? |
4 layers: thin
5 layers: thick |
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Name the layers of the epidermis:
C L G S B |
Stratum corneum
Stratum Lucidum (+ -) Stratum Granulosum Stratum Spinosum Stratum Basale |
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Stratum layer that is 20-30 layers thick. 3/4 of epidermal thickness. Dead, completely filed with keratin.
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Stratum Corneum
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Clear Layer, Present only in thick skin
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Stratum Lucidum
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Stratum layer of 3-5 layers of cels where keratinization begins. Langerhans cells found here.
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Stratum Granulosum
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Stratum layer with spiney projections. Some mitosis occurs. Langerhans nd keratinocytes found here
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Stratum spinosum
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Stratum layer with wingle layer of cuboidal to columnar shaped cells. Seperated from the dermis by the BM. Many mitotic cells here 25% are melanocytes.
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Stratum basale
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What cell types are found in the dermis?
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fibroblasts, macrophages, some mast cells and white blood cells
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What are the 2 layers of the dermis?
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Papillary
Reticular |
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Superficial layer of the dermis. Very vascular. Arranged in patterns that make whirled loops on the ventral sides of the hands and feet.
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Papillary Layer
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What 3 pigments contribute to the skins color?
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1. melanin
2. carotene 3. hemoglobin |
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What are 3 effects of increases exposure to UV radiation?
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1. Clumping of elastin fibers leasing to "leathery" skin
2. temporarily depresses the immune system 3. can alter the DNA od skin cells leading to cancer. |
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What are the appendages of the skin?
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1. hairs
2. hair folicles 3. nails 4. sweat glands 5. sebaceous glands all 5 are derived from the epidermis |
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What is the function and structure of hair?
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function: protect head from trauma, heat loss and sunlight. shield dust-eyelashes and nose hairs
structure: 3 concentric layers of keratinized cells 1. core-mdulla 2. cortex-bulky layer 3. cuticle-outer strong layer |
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Sensory nerve ending that wraps around the hair follicle bulb
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root hair plexus
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nipple like knot of capillary tissue that protrudes into the hair bulb and supplies it with nutrients.
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Papila
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structures associated with hair folicles
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1. nerve endings 2. sebaceous glands 3. smooth muscle sructure (involuntary)-arrector pili
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goose bumps are a result of this smooth muscle contracting
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arrector pilli
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Lips, nipples, external genitalia and the thick areas of the hands and feet lack this
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hair
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2 types of hair:
thin hair is called ? thicker coarser hair is called? |
vellus
terminal |
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2 factors that can influence hair growht and density:
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1. nutrition
2. hormones |
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2 types of sweat glands and where are they found?
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1. eccrine- palms,soles and forehead 99% water
2. apocrine- found in the auxillary and anogenital regions. secrete water along with fatty substance and proteins. odorless until bacterial decomposition occurs |
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Secretes ear wax
Secretes milk |
Ceruminous Glands
Mammary Glands |
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Secretes sebum. softens and lubricates hair and skin. Antibacterial properties.
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Sebaceous Glands
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Bacteri responsible for acne
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staphylococcus
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Least malignant skin cancer. cells in the stratum _ are altered and can't form _.
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Basal Cell Carcinoma
Stratum Basale Keratin |
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Arises from keratinocytes in the stratum _. causes red papule found most often on the scalp, ears,dorsum of the hands and lower lip.
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Squamous Cell Carcinoma
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Deadly cancer of the _. Begins wherever there is pigment present.
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Malignant Melanoma
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Describe the ABCD rule for evaluating skin lesions
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A. Assymmetry - 2 sides dont match
B. Border - irregular, not smooth C. Color - pigmented spot d. Diameter - larger than 6mm |