The integumentary system

  1. The organs of the integumentary system include
    are what?
    the skin and its accessory structures including hair, nails, and glands, as well as blood vessels, muscles and nerves
  2. Dermatology is what?
    The medical specialty for the diagnosis and treatment of disorders of the integumentary system.
  3. Clinical term for "skin"
    cutaneous membrane
  4. Where is skin the thickest?
    The heels
  5. Where is skin the thinnest?
    The eyelids.
  6. Outer, thinner layer of skin is called ?
    The epidermis
  7. What is the Epidermis made of?
    epithelial tissue
  8. What is the "dermis"?
    inner, thicker layer of skin
  9. What lies beneath the dermis?
    A subcutaneous (subQ) layer (also called hypodermis) which attaches the skin to the underlying tissues and organs.
  10. What is the epidermis made of?
    The epidermis is composed of keratinized stratified squamous epithelium
  11. What are the 4 major types of cells in the epidermis?
    • Keratinocytes
    • Melanocytes
    • Langerhans
    • Merkel
  12. What do Merkel cells do?
    function in the sensation of touch along with the adjacent tactile discs
  13. What do Langerhans cells do?
    involved in immune responses, arise from red bone marrow
  14. What do Melanocytes do?
    produce the pigment melanin that protects against damage by ultraviolet radiation
  15. What do Keratinocytes do?
    (90% of the cells) produce keratin which is a tough fibrous protein that provides protection
  16. I.D. the cell
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  17. ID the cell
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  18. ID the cell
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  19. ID the cell
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  20. Review
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  21. List the layers of the epidermis.
    • Stratum basale
    • Stratum spinosum
    • Stratum granulosum
    • Stratum lucidum
    • Stratum corneum
  22. composed of many sublayers of flat, dead keratinocytes called that are continuously shed and replaced by cells from deeper strata; constant friction can stimulate formation of a callus.
    Stratum corneum
  23. where continuous cell division occurs which produces all the other layers
    Stratum basale
  24. 8-10 layers of keratinocytes
    Stratum spinosum
  25. comprised of keratinocytes with lamellar granules
    Stratum granulosum
  26. present only in thick skin (the skin of the fingertips, palms, and soles)
    Stratum lucidum
  27. What is Keratinization?
    The accumulation of more and more protective keratin, occurs as cells move from the deepest layer to the surface layer
  28. ID the Layers Top to Bottom.
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    •Stratum corneum

    •Stratum lucidum

    •Stratum granulosum

    •Stratum spinosum

    •Stratum basale
  29. Stratum Basale
    •Deepest single layer of cells

    •Called stratum germinativum

    • •Combination of merkel cells, melanocytes, keratinocytes &
    • stem cells that divide repeatedly

    • •Cells attached to each other & to
    • basement membrane by desmosomes & hemidesmosomes
  30. Stratum Spinosum
    •8 to 10 cell layers held together by desmosomes

    • •During slide preparation, cells shrink
    • and look spiny

    • •Melanin taken in by phagocytosis from
    • nearby melanocytes
  31. Stratum Granulosum
    •3 - 5 layers of flat dying cells

    •Show nuclear degeneration

    •Contain dark-staining granules

    • •Contain lamellar granules that release
    • lipid that repels water
  32. Stratum Lucidum
    • •Seen in thick skin on palms & soles
    • of feet

    • •Three to five layers of clear, flat,
    • dead cells

    •Contains precursor of keratin
  33. Stratum Corneum
    • •25 to 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
  34. What produces keratinocytes?
    Stem cells divide to produce keratinocytes
  35. This is composed of connective tissue containing collagen and elastic fibers
  36. What are the 2 layers of the dermis?
    • •the outer papillary region consists of areolar connective tissue containing thin collagen and elastic fibers, dermal papillae, corpuscles of touch and free nerve endings
    • •The deeper reticular region consists of dense irregular connective tissue containing collagen and elastic fibers adipose cells, hair follicles, nerves, sebaceous (oil) glands, and sudoriferous (sweat) glands
  37. can appear if the skin is stretched too
    Striae or stretch marks
  38. Finger like projections called dermal
    papillae create fingerpints.
  39. What are the functions of the papillary region?
    –anchors epidermis to dermis

    • –contains capillaries that feed
    • epidermis

    • –contains Meissner’s
    • corpuscles (touch) & free nerve endings (pain and temperature)
  40. •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 of the dermis
  41. What do Epidermal ridges do?
    reflect contours of the underlying dermal papillae and form the basis for fingerprints (and footprints); their function is to increase firmness of grip by increasing friction.
  42. Variations in skin color arise from variations in the amounts of three pigments:
    melanin, carotene, and hemoglobin
  43. Where is Melanin located and how is it produced?-
    • produced by melanocytes (located
    • mostly in the epidermis, where it absorbs UV radiation)
  44. Why are people different colors?
    differences in skin color is due to the amount of pigment produced
  45. What is Carotene?

    Hemoglobin - red color (located in erythrocytes
    yellow-orange pigment (found in the stratum corneum, dermis, and subcutaneous layer)
  46. is not part of the skin but, among its
    functions, it attaches the skin to the underlying tissues and organs
    Subcutaneous (subQ) layer
  47. contains lamellated (pacinian) corpuscles which
    detect external pressure applied to the skin.
    Subcutaneous Layer
  48. Hair is composed of what?
    dead, keratinized epidermal cells
  49. What are the parts of the pillie (hair)?
    •root which penetrates into the dermis

    •hair follicle

    •epithelial root sheath

    •dermal root sheath
  50. What are the functions of hair?
    •Prevents heat loss

    •Decreases sunburn

    •Eyelashes help protect eyes

    • •Touch receptors (hair root plexus)
    • senses light touch
  51. Name the glands of the skin.
    •Sebaceous (oil) glands

    • •Sudoriferous (sweat)
    • glands

    • •Ceruminous (wax)
    • glands

    •Mammary (milk) glands
  52. Sebum does what?
    • –combination of cholesterol, proteins,
    • fats & salts

    –keeps hair and skin soft & pliable

    • –inhibits growth of bacteria &
    • fungi(ringworm)
  53. What are the 2 types of sweat glands?
    • Eccrine
    • Apocrine
  54. These are found in most areas of skin contain a secretory portion in dermis with duct to surface and regulate body temperature with perspiration
    Eccrine (sweat) glands
  55. These are found in the armpit and pubic region contain secretory portion in dermis with duct that opens onto hair follicle and secretions more viscous
    Apocrine (sweat) glands
  56. Where would you find Ceruminous Glands?
    The ear.
  57. What are nails?
    Tightly packed, keratinized cells
  58. ID the more prominent features from L-R
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    • Nail Root
    • Cuticile
    • Luluna
    • Nail Bed
    • Free Edge
    • Nail Matrix
  59. What are the general functions of skin?
    •Regulation of body temperature

    •Protection as physical barrier

    •Sensory receptors

    •Excretion and absorption

    •Synthesis of vitamin D
  60. How does skin aid in thermoregulation?
    •Releasing of sweat onto the skin

    • Adjusting flow of blood to the body
    • surface

    • Shivering and constriction of surface
    • vessels
  61. How does the skin provide protection?
    • –tight cell junctions prevent bacterial
    • invasion

    –lipids released retard evaporation

    • –pigment protects somewhat against UV
    • light

    • –langerhans cells
    • alert immune system
  62. True or False?
    Lipid soluble substances can be absorbed through the skin
  63. What are 3 most common types of skin cancer?
    –basal cell carcinoma (rarely metastasize)

    • –squamous cell
    • carcinoma (may metastasize)

    –malignant melanomas (metastasize rapidly)
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The integumentary system
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