Ch 5 quiz questions plain text.txt

  1. skin facts
    • - largest organ in the body
    • - 16% of body weight
  2. epidermis characteristics
    • - avascular
    • - composed of keratinized stratified squamous epithelium
    • - contains 4 layers (thin skin) or 5 (thick skin)
  3. epidermal layers
    • stratum basale: deepest layer, where mitosis occurs, sites of Merkel cells and melanocytes (this layer also called stratum germinativum)
    • stratum spinosum: 8-10 layers of keratinocytes (site of Langerhans cells)
    • stratum granulosum: transition to dead keratinocytes (cells undergo apoptosis), lamellar granules form, which are lipid secretions that help fill the space in this and the remaining layers, also acts as a water repellant
    • strata lucidum (only in thick skin): dead cells in palms and soles)
    • stratum cortex: outer surface - contains flat dead keratinocytes (callus forms with constant friction)
  4. 4 types of epidermal cells
    • - keratinocytes
    • - melanocytes
    • - merkel cells
    • - Langerhans cells
  5. keratinocytes
    • makes keratin, which is a fibrous protein that provides PROTECTION
    • about 90% of the cells in the epidermis
  6. melanocytes
    makes melanin, which acts to protect the nucleus of keratinocytes against UV radiation
  7. Langerhans cells
    involved in immune response (ie: with HPV or gonorrhea, pus comes out of genitals due to langerhans cells immune response). cells come from RED bone marrow
  8. Merkel Cells
    involved in sensation of touch - have nerve structures that they are in contact with (deep in the epidermis)
  9. keratinization
    process of keratin accumulation as going from the stratum basale to the stratum cortex
  10. dandruff
    dead keratinized cells shedding from the scalp
  11. dermis characteristics
    • vascular
    • elastic, resulting in the cause of stretch marks and wrinkles due to too much stretching
    • composed of connective tissue containing collagen and elastic fibers
  12. dermal layers
    • papillary region: superficial region that is 1/5 of the dermis, has nerve endings and areolar connective tissue containing collagen and elastic fibers
    • reticular region: deeper region, has dense irregular connective tissue containing collagen and elastic fibers, adipose cells, hair follicles, nerves, sebaceous glands (oil) and sudoriferous glands (sweat)
  13. how can skin color vary
    • different amounts of 3 pigments
    • 1. melanin
    • 2. carotene
    • 3. hemoglobin
  14. melanin
    yellow-red or brown-black pigment produced by melanocytes. People have similar amount of melanocytes, but differences in production of melanin determine skin color
  15. how does a mole form
    a mole (nevus) forms from a localized overgrowth of melanocytes
  16. carotene
    yellow-orange pigment found in stratum corteum, subcutaneous layer and dermis
  17. hemoglobin
    red color pigment from erythrocytes (RBCs) flowing in dermal capillaries
  18. subcutaneous layer
    below the dermis, not actually part of the skin. Attaches to underlying tissue and organs. contains LAMELLATED Corpuscles that detect external pressure applied to skin
  19. hair
    • composed of dead keratinized cells
    • shaft: projects above the surface of the skin (composed of medulla, cortex and cuticle)
    • root: penetrates into dermis (more layers, same as above but after cuticle there is an inner, external and dermal root sheath (furthest out)
    • epithelial root sheath: consists of inner and external roof sheaths
  20. arrector pili
    muscle around hair that makes it stand up when cold, for example
  21. oil glands
    sebaceous glands: connected to hair follicles, secrete sebum - oil that prevents dehydration of hair and skin and kills some bacteria
  22. sweat glands
    • sudoriferous glands - there are two types
    • eccrine: helps to cool the body by evaporating, also eliminates waste (ions such as salt, ammonia and urea)
    • apocrine: located mainly in the skin of axilla and groin, secretes when physical, emotional stress. hypohydrosis is excessive sweating (can be treated with bottom)
  23. Skin types
    • thick skin: palms and digits and soles (contains stratum lucid)
    • thin skin: other parts of the body (also called hairy)
  24. nails
    • composed of keratinized cells, have 3 parts
    • free edge
    • transparent nail body
    • nail root
  25. Skin FUNCTIONS
    • 1. protection
    • 2. absorption and secretion
    • 3. regulation of body temperature
    • 4. blood reservoir
    • 5. site of vitamin D synthesis
    • 6. cutaneous sensations
  26. Types of wound healing
    • epidermal wound healing: basale epithelial cells migrate towards each other and fill the gaps
    • deep wound healing: blood clots, then the SCAB forms as the new cells fill the gaps and push the blood clot to the surface.
Card Set
Ch 5 quiz questions plain text.txt