Anatomy Chapter 5

  1. integumentary system
    first line of defense aainst a hostile environment - cutaneous membrane and accessory structures
  2. 6 functions of skin and subcutaneous layer
    • 1. protect
    • 2. excrete
    • 3. regulate temperature
    • 4. synthesis of vitamin D
    • 5. storage of nutrients
    • 6. touch sensation (pressure, pain, temperature)
  3. the epidermis consists of what type of epithelium?
    stratified squamous
  4. the epidermis is:
    a) vascular
    b) avascular
    • the epidermis is:
    • a) vascular
    • b) avascular - cells rely on the diffusion capillaries within the dermis
  5. thick skin
    contains 5 layers found on the soles and palms
  6. thin skin
    contains only 4 layers found everywhere except soles and palms
  7. skin color
    a result of epidermal pigmentation
  8. melanin
    brown color
  9. carotene
    can be converted to Vitamin A - yellow
  10. layers of the epidermis - in order from basal lamina to the free surface
    • cells flatten and fill with the protein keratin as they rise to the surface:
    • stratum germinativum
    • stratum spinosum
    • stratum granulosum
    • stratum lucidum
    • stratum corneum
  11. stratum germinativum
    aka basale - deepest epidermal layer, attached to the basmement mebrane (dermis
  12. fingerprints are formed by...
    layers of the epidermis touching the ridges of the dermal papilla layer of the dermis
  13. basal cells
    stem cells that are constantly dividing - part of the stratum germinativum
  14. merkel cells
    function as touch sensitive receptors for the nervous system within the stratum germinativum layer of the epidermis
  15. melanocytes
    produce melanin when stimulated by UV light
  16. stratum spinosum
    superficial to the stratum germinativum (8-10 layers of cells)
  17. keratinocytes
    produce keratin which is used for structure and water resistance
  18. langerhans cells
    stimulate and assist the immune system upon penetration by pathogens
  19. stratum granulosum
    3rd epidermal layer - where cells fill with keratin and die
  20. stratum lucidum
    extra layer in thick skin - cells completely filled with keratin
  21. stratum corneum
    exposed surface of both thick and thin skin, 15-300 layers of keratinized cells, protective barrier of dead, durable and expendable cells protecting underlying epidermal layers, constantly being sloughed or shed off (15-30 days to rise, stay for approximately 2 weeks)
  22. epidermal growth factor - 4 effects on epithelia
    • 1. promote the divisions of germinative cells
    • 2. increase the production of keratin
    • 3. stimulate secretion by epithelial glands
    • 4. stimulate epidermal repair after injury
  23. the dermis
    contains blood vessels, glands, and accessory structures - lies between the epidermis and the subcutaneous layer
  24. 2 major layers of the dermis
    • 1. papillary layer
    • 2. reticular layer
  25. papillary layer
    composed of loose connective tissue - meissner's corpuscles
  26. reticular layer
    composed of dense irregular connective tissue - pacinian corpuscles
  27. meissner's corpuscles
    sensitive to light touch
  28. pacinian corpuscles
    sensitive to deep pressure and vibration
  29. the subcutaneous layer consists of what types of tissues?
    aka: hypodermis - consists of adipose and areolar tissues - very elastic
  30. 3 types of accessory structures
    • 1. hair
    • 2. glands
    • 3. nails
  31. hair
    approx. 5 million that have very little function (slightly insulate skin surface, provide UV protection, filter air the passes into/by the body surface)
  32. hair shaft
    above surface
  33. hair root
    below surface
  34. 2 types of hair
    • 1. vellus hair
    • 2. terminal hair
  35. vellus hair
    fine, lightly pigmented - covering the majority of the body surface
  36. terminal hair
    thick, pimented - found on top of head, eyebrows, eyelashes
  37. scalp hair timing...
    remains attached and growing for 2-5 years (average adult scalp loses approx. 50 hairs a day)
  38. hair color
    determined by the type and amount of melanin produced by the follicle
  39. gray hair is a result of...
    pigment production slowing with age - bubbles are produced in the medullary (middle layers)
  40. follicles
    where hair originates - deep through the dermis and into the hypodermis terminating at the bulb
  41. arrector pili muscles
    muscles associated with each hair root - can be pulled upright to cause goosebumps
  42. cuticle
    hard, dead, keratinized cells that cover hairs
  43. cortex
    contains hard keratin
  44. medulla
    contains soft, flexible keratin
  45. 4 types of glands
    • 1. sebaceous (oil) glands
    • 2. sudiferous/sweat glands
    • 3. mammary glands
    • 4. ceruminous glands
  46. sebaceous glands
    oil glands - secrete sebum (waxy, oily substance) into the hair follicle by holocrine secretion - functions to keep hair and skin smooth and supple
  47. 2 types of sudiferous/sweat glands
    • a. apocrine
    • b. merocrine
  48. apocrine sweat glands
    located in pubic and axillary areas - begin to secrete sticky, cloudy, odor-producing secretions into hair follicles at puberty
  49. merocrine (eccrine) sweat glands
    located over entire body surface, but highly concentrated on palms and soles - secrete sweat directly to skin surface
  50. mammary glands
    modified apocrine glands whose secretions are highly regulated by ffemale sex hormones
  51. ceruminous glands
    modified sweat glands that secrete cerumen (earwax) in external auditory canal
  52. nails
    plates of keratin located on the dorsal ends of fingers and toes that protect digits from mechanical stress
  53. aging effects on the integumentary system
    • Epidermis thins
    • Vitamin D3 levels decrease by 75%
    • Melanocyte activity declines, skin becomes pale
    • Glandular activity declines
    • Merocrine sweat glands are less active, older people cannot loose heat as fast as young people
    • Blood supply to the dermis is reduced
    • Hair follicles stop functioning or produce thinner, finer hairs, hair grays
    • Dermis thins
    • Secondary sexual characteristics fade
    • Skin repairs proceed slowly, recurring infections may result.
Card Set
Anatomy Chapter 5
Integumentary System