Derm1- Structure Function

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  1. What are the layers of the skin?
    • Epidermis (stratified squamous epithelium)
    • Dermal-Epidermal junction (basement membrane)
    • Dermis (connective tissue)
    • Adnexae (follicles/glands)
    • Hypodermis/ SubQ (adipose tissue)
  2. What are the components of the epidermis? (3)
    keratinocytes, melanocytes, Langerhans cells (dendritic cells)
  3. What are the 4 layers keratinocytes of the epidermis?
    • stratum corneum (superficial)
    • stratum granulosum
    • stratum spinosum
    • stratum basale (right above BM)
  4. How are cells of the epidermis organized?
    by stages of differentiation: least differentiated in stratum basale
  5. How are stratum basale cells attached to the BM? (3)
    interdigitating foot processes, hemidesmosomes, anchoring fibrils (go through BM)
  6. What are the main functions of the stratum basale? (2)
    keratinocyte progenitors, anchor epidermis to dermis
  7. What are the intercellular attachments b/w cells of the stratum spinosum?
    desmosomes (b/w cells- anchor cells to one another)
  8. What are the intracellular attachments b/w cells of the stratum spinosum?
    tonofilaments (within cell- anchor desmosomes to cell membrane)
  9. What are the components of the stratum granulosum? (2)
    lamellar granules (phospholipid), keratohyaline granules (fibrous proteins called filaggrin to provide cross-linking)
  10. What is characteristic of the stratum corneum?
    anuclear dead cells that form a dense marginal band that is hydrophobic and impermeable
  11. In health, the rate of maturation/differentiation of skin ___________ the rate of desquamation.
    equals
  12. Hyperplasia of stratum spinosum.
    acanthosis
  13. Hyperplasia of stratum corneum.
    hyperkeratosis
  14. How does malnutrition affect the skin?
    suboptimal production of keratinocytes--> poor hair quality, incompetent skin barrier
  15. What nutrients are required for keratinization and maturation of the epidermis? (3)
    Vit A, Zn, Cu
  16. Melanocytes are ______ cells in the stratum _________.
    "clear"; basale
  17. What is the function of melanocytes? (2)
    melanin synthesis and transfer to keratinocytes
  18. What is the purpose of melanin?
    located perinuclearly in keratinocytes to protect DNA from UV light, free radicals, and heat
  19. The concentration of epidermal melanin is a factor of... (3)
    # of melanocytes, rate of melanin synthesis, and transfer/loss of melanin.
  20. Melanin synthesis is inhibited by... (3)
    Cu deficiency, corticosteroids, inflammation
  21. Why is Cu important for melanin synthesis?
    Cu is a cofactor for Tyrosinase, which is a key enzyme in melanin production
  22. What processes can cause hypo-pigmentation? (3)
    decreased replication of melanocytes (age, genetics), destruction of the EMU (epidermal melanin unit- inflammation), decreased melanin synthesis (Cu deficiency)
  23. What are generalized and focal manifestations of decreased melanogenesis? (G- 3, F- 3)
    • Generalized- albinism, piebald, color dilution
    • Focal- vitiligo, leukoderma, leukotrichia
  24. What processes can cause hyper-pigmenation? (3)
    increased melanocyte proliferation, increased melanin synthesis, increased exposure to UV/MSH/ACTH
  25. What are specific disorders that can cause hyper-pigmentation? (3)
    lentigo, chronic irritation, inflammation
  26. Langerhans cells are _______ cells located within the stratum _________.
    clear; basale
  27. What are the functions of Langerhans cells? (3)
    trap and process antigens, resistance, immune surveillance
  28. Band of fibrillary proteins at the dermal-epidermal junction.
    basement membrane
  29. What are the functions of the dermal microfibril bundles and anchoring fibrils at the dermal-epidermal junction? (3)
    anchoring BM to dermis, epidermal maintenance, wound healing
  30. What causes scar formation?
    loss of BM with abrasion
  31. Heterogenous group of diseases characterized by blistering/ulceration of the skin and mucous membrane epithelium following minor mechanical trauma.
    epidermolysis bullosa
  32. Epidermolysis bullosa is caused by abnormalities at the level of... (2)
    basal cells or BM proteins.
  33. Mechanoboullous disease is a(n) __________.
    epidermal separation (epidermolysis bullosa)
  34. Diseases in which antibodies are directed again self-antigens and Ag-Ab complexes are deposited on the BM, leading to tissue damage and bullae formation, vesicles, and ulcers. (2)
    [immune-mediated diseases- type III hypersensitivity] systemic lupus erythematosus (SLE) and discoid lupus erythematosus (DLE)
  35. Ag-Ab complex deposition on the BM due to immune-mediated disease leads to... (4)
    damage to epidermal BM, bullae, vesicles, and ulcers.
  36. The dermis is a(n) _________ tissue with __________.
    fibroelastic; interfibrillar spaces (sponge-like)
  37. What are the 2 types of dermis?
    papillary dermis (fine, loose collagen rich in vessels and nerves), reticular dermis (thick, subjacent dermis with coarse collagen)
  38. What are the components of the dermis? (2)
    What are their functions?
    collagen/elastin/reticulin and ground substance (acellular- structural support), fibroblasts/macs/T cells/mast cells/DC (cellular component- produces matrix and tissue response)
  39. Disease that is a defect in collagen production, quality, or packaging, leading to abnormal tensile properties of the dermis (stretchy skin OR friable skin).
    skin fragility syndrome
  40. Functions of hair and feather follicles. (3)
    productions/attachment/support of hair and feathers, re-epithelialization and repair, reservoir of resistance factors
  41. Functions of hair and feathers. (3)
    thermoregulation, physical protection, photoprotective
  42. What are the 3 phases of hair/feather growth?
    • anagen phase- growth
    • catagen phase- transition
    • telogen- resting
  43. What are the controls of the cyclical proliferation and exfoliation of hair and feathers? (5)
    hormones, daylight, temperature, nutrition, and growth factors
  44. Abnormal formation of the hair shaft.
    follicular dysplasia
  45. Genetic, ischemic, traumatic, metabolic, or inflammatory damage to the follicle, causing hair loss.
    follicular atrophy (most common disorder of the hair follicle- alopecia without associated inflammation [contrast to folliculitis])
  46. Inflammation of follicles caused by bacteria, mites, fungi, etc.; accompanied by signs of inflammation and alopecia.
    folliculitis
  47. Folliculitis with rupture of the hair follicle.
    furunculosis
  48. Sebaceous glands are adjacent to _________ and have a duct that opens to the _________.
    follicles; infundibulum (uppermost part of hair follicle)
  49. How do sebaceous glands release sebum?
    holocrine gland- basal cells differentiate into sebum-producing cells, which die and release sebum into duct
  50. What hormones cause atrophy and involution of sebaceous glands, causing alopecia, seborrhea, and dry skin. (2)
    estrogens and glucocorticoids
  51. What hormones have increased activity of sebaceous glands? (1)
    androgens
  52. Apocrine glands line the __________ and have a duct that opens to the __________.
    tubular lumina of the hair follicle; infundibulum (uppermost part) of the hair follicle
  53. What are the functions of apocrine glands? (2)
    thermoregulation/surface emulsion, antimicrobial (IFN, transferrin, NaCl, complement)
  54. How do apocrine glands secrete sweat?
    merocrine glands- actively secrete product
  55. With chronic otitis externa, ____________ become _________, causing suppurative adenitis.
    cystic ceruminous glands; hyperplastic
  56. What are the functions of the arrector pili muscle? (2)
    piloerection for thermogenesis and barrier, contraction facilitates excretion of follicular secretions (apocrine and sebaceous gland products)
  57. Why do your dog's hackles stand up when scared?
    arrector pili muscle has sympathetic innervation
  58. What is an important function of the skin vasculature?
    readily responds to and participates in inflammation of the skin
  59. Congestion of the skin is a(n) __________ process; hyperemia is a(n) __________ process.
    passive; active
  60. Hemorrhage of the skin clinically appears as... (2)
    petechiae and ecchymoses
  61. Infarction of skin vessels can be caused by... (3)
    bacterial emboli, DIC, vasculitis
  62. What causes pruritus?
    inflammation that stimulates the local nerve endings of the skin
  63. Tactile hairs/whiskers that are special sensory follicles and are highly innervated.
    vibrissae
  64. The hypodermis is the deep layer of ___________.
    fibroadipose tissue
  65. What are the functions of the hypodermis? (3)
    insulation, protection, and energy storage
  66. List a few disorders of the dermal-epidermal junction. (3)
    epidermolysis bullosa, SLE, DLE (lupus erythematosus)
  67. List a few disorders of the dermis. (2)
    skin fragility syndrome (genetic-collagen dysplasia and acquired- cushing's, DM, hepatic dz)
  68. List some disorders of the follicle. (5)
    follicular atrophy, follicular dysplasia, abnormal growth (endocrine, metabolic), folliculitis, furunculosis
  69. List a few disorders of sebaceous glands. (3)
    sebaceous atrophy (endocrine, metabolic), sebaceous adenitis (autoimmune), adenomas
  70. List a few disorders of apocrine glands. (4)
    Hidradenitis (secondary to bacterial infection or trauma), ceruminous adenitis secondary to otitis externa, anal sacculitis, anal gland carcinoma
  71. List a few signs of disorders of the vascular supply to the skin. (2)
    petechiae/ecchymoses (hemorrhage), DIC/vasculitis (infarction)
Author:
Mawad
ID:
314016
Card Set:
Derm1- Structure Function
Updated:
2016-01-13 20:15:30
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vetmed derm1
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vetmed derm1
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