1. System that includes the skin and its derivatives
    Integumentary System
  2. What the derivatives of skin?
    • Hair
    • Nails
    • Glands
  3. Epithelial layer of skin
  4. Layer of connective tissue, nerve & muscle
  5. What is the Subcutaneious tissue (subQ or hypodermis)?
    A layer of adipose & areolar tissue located below the dermis
  6. Composed of keratinized stratified squamous epithelium
  7. Contains no blood vessels
  8. 4 types of cells in it
  9. Has 4/5 distinct strata (layers) of cells
  10. What are the four cell types of the epidermis?
    • 1. Keratinocytes (90%)
    • 2. Melanocytes
    • 3. Langerhan cells
    • 4. Merkel cells
  11. Produces keratin
  12. Produces melanin pigment
  13. How is melanin transferred to other cells?
    With long cell processes
  14. From bone marrow (modified monocytes)
    Provide immunity (ingest bacteria and viruses)
    Langerhan cells
  15. In deepest layer
    Form touch receptor with sensory neuron
    Merkel cells
  16. Deepest single layer of cells
    Called stratum germinativum
    Stratum Basale
  17. Combination of merkel cells, melanocytes, keratinocytes & stem cells that divide repeatedly
    Cells attached to each other and to basement membrane
    Stratum Basale
  18. 8-10 cell layers held together by desmosomes
    Stratum Spinosum
  19. Stratum Spinosum:
    What happens to the cells during slide preparation?
    Cells shrink and look spiny
  20. Stratum Spinosum: How is melanin taken in?
    By phagocytosis from nearby melanocytes
  21. 3-5 layers of flat dying cells
    Show nuclear generation
    Contain dark-staining keratohylin granules
    Stratum Granulosum
  22. 3-5 layers of clear, flat, dead cells
    Contains precursor of keratin
    Seen in thick skin on palms & soles of feet
    Stratum Lucidum
  23. 25-30 layers of flat dead cells filled with keratin and surrounded by lipids
    Continuously shed
    Barrier to light, heat, water, chemicals & bacteria
    Friction stimulates callus formation
    Stratum Corneum
  24. What are the two types of skin?
    • Thin skin
    • Thick skin
  25. Describe thin skin (3 points)
    • Covers most of body
    • Thin epidermis that lacks stratum lucidum
    • Lacks epidermal ridges, has fewer sweat gladns and sensory receptors
  26. Describe thick skin (3 points)
    • Only on palms and soles
    • Thick epidermis with distinct stratum lucidum & thick stratum corneum
    • Lacks hair follicles and sebaceous glands
  27. Describe the process of Keratinization & Epidermal Growth
    • 1. Stem cells divide to produce keratinocytes
    • 2. As keratinocytes are pushed up towards the surface, they fill with keratin
    • 3. 4 week journey unless outer layers removed in abrasion
  28. Connective tissue layer composed of collagen & elastic fibers, fibroblasts, macrophages & fat cells
    Contains hair follicles, glands, nerves & blood vessels
  29. What are the 2 major regions of dermis?
    • Papillary region
    • Reticular region
  30. Top 20% of dermis
    Composed of loose CT & elastic fibers
    Finger like projections called dermal papillae
    Papillary Region
  31. What are the 3 functions of the papillary region?
    • 1. anchors epidermis to dermis
    • 2. contains capillaries that feed epidermis
    • 3. contains Meissner’s corpuscles (touch) & free nerve endings (pain and temperature)
  32. Dense irregular connective tissue
    Contains interlacing collagen and elastic fibers
    Packed with oil glands, sweat gland ducts, fat & hair follicles
    Provides strength, extensibility & elasticity to skin– stretch marks are dermal tears from extreme stretching
    Reticular Region
  33. Where do epidermal ridges form?
    In fetus as epidermis conforms to dermal papillae
  34. What do epidermal ridges give us? (2 things)
    • 1. Fingerprints are left by sweat gladns open on ridges
    • 2. Increase grip of hand
  35. What are the 7 functions of skin?
    • Protection
    • Regulation of body temperature
    • Immunity
    • Excretion
    • Blood reservoir
    • Synthesis of vitamin D
    • (PRIEBS)
  36. What is Thermoregulation?
    • Releasing of sweat onto the skin
    • -perspiration and its evaporation lowers body temperature
  37. Adjusting flow of blood to body surface:
    What happens during moderate exercise?
    More blood brought to surface helps lower temperature
  38. Adjusting flow of blood to the body surface:
    What happens with extreme exercise?
    Blood is shunted to muslces and body temperature rises
  39. What do humans do to raise internal body temperature as needed?
    Shiver and constrict surface vessels
  40. How does skin provide protection? (4 points)
    • Physical, chemical and biological barrier:
    • 1. Tight cell junctions prevent bacterial invasion
    • 2. Lipids released retard evaporation
    • 3. Pigment protects somewhat against UV light
    • 4. Langerhans cells alert immune system (antigen presenting to T-lymphocytes
  41. Touch, temperature, pressure, vibration, tickling and pain sensations arise from the skin
    Cutaneous Sensations
  42. Only a minor role is played by the skin
    400 mL of water evaporates from it daily
    Small amounts salt, CO2, ammonia and urea are excreted
    Lipid soluble substances can be absorbed through the skin
    – vitamins A, D, E and K, Oxygen and CO2
    – acetone and dry-cleaning fluid, lead, mercury, arsenic, poisons in poison ivy and oak
  43. Blood can be stored in venous vessels located in the dermis and hypodermis
    Blood Reservoir
  44. Describe the synthesis of Vitamin D?
    • 1. Sunlight activates a precursor to vitamin D
    • 2. Enzymes in the liver and kidneys transform that molecule into calcitriol (most active form of vitamin D)
  45. Why is vitamin D important?
    Necessary vitamin for absportion of calcium from food in the gastrointestinal tract
  46. How are hair, oil glands, sweat glands and nails formed?
    Cells sink inward during development
  47. What are the 4 functions of hair?
    • 1. Prevents heat loss
    • 2. Decreases sunburn
    • 3. Eyelashes help protect eyes
    • 4. Touch receptors (hair root plexus) senses light touc
  48. What are the 3 parts of the hair shaft?
    • 1. Medulla
    • 2. Cortex
    • 3. Cuticle
  49. What ar the 3 part so the hair structure?
    • Shaft (visible)
    • Root (below the surface)
    • Folllicle (surrounds root)
  50. What is the base of the follicle called and what does it have?
    • bulb
    • -blood vessels
    • -germinal cell layer
  51. What is the difference between the external root sheath and the internal root sheath?
  52. Smooth muscle in dermis contracts with cold or fear
    Forms goosebumps as hair is pulled vertically
    Arrector pili
  53. Detects hair movement
    Hair root plexus
  54. How does hair have color?
    Result of melanin produced in melanocytes in hair bulb
  55. True or false: Dark hair contins true melanin
  56. What does blonde and red hair contain?
    Melanin with iron and sulfur added
  57. Why does hair go grey?
    Result of decline in melanin production
  58. Why does hair go white?
    White hair has air bubbles in the medullary shaft
  59. Oil glands
    Sebacious glands
  60. Sweat glands
    Sudiferous glands
  61. Wax glands
    Ceruminous glands
  62. Milk glands
    Mammary glands
  63. Secretory portion in the dermis
    Located on most of body except palm of hands and sole of feet
    Most open onto hair shafts
    Sebaceous glands
  64. Combination of cholesterol, proteins, fats & salts
    Keeps hair and skin soft & pliable
    Inhibits growth of bacteria & fungi(ringworm)
    Holocrine type of excretion
  65. Bacterial inflammation of glands
    Secretions stimulated by hormones at puberty
  66. Most areas of skin
    Secretory portion in dermis with duct to surface
    Regulate body temperature with perspiration
    Eccrine-Merocrine (sweat) glands
  67. Which glands:
    Armpit and pubic region
    Secretory portion in dermis with duct that opens onto hair follicle
    Secretions more viscous
    Apocrine (sweat) glands
  68. What are the two types of sweat glands?
    • Eccrine-Merocrine glands
    • Apocrine glands
  69. What are nails composed of?
    Tightly packed keratinized cells
  70. What is the nail body pink?
    • Visible portion pink due to underlying capillaries
    • Free edge appears white
  71. Which part of the nail is...
    Buried under skin layers
    Lunula is white due to thickened stratum basale
    Nail root
  72. Which part of the nail is...
    Stratum corneum layer
    Eponychium (cuticle)
  73. What are the 4 functions of nails?
    • 1. Enhance grasping
    • 2. Manipulate objects
    • 3. Protection against trauma to ends of digits
    • 4. Scratching body part
Card Set
Integ 1