Properties of hair and skin.txt

  1. What is skin
    It is the largest organ of the body
  2. Skin is our only barrier against the
  3. What should healthy skin be
    Slightly moist, soft, and flexible
  4. The skin of the scalp is constructed similarly the skin elsewhere on the body but the scalp has what to accommodate the longer hair of the head
    larger and deeper hair follicles
  5. What is vellus or lanugo hair
    It is short fine and downy hair it is commonly found on infants as well as on adults but it is on areas usually considered hairless except the palms of the hands and the soles of the feet
  6. What is terminal hair
    Long hair found on the scalp legs arms and body it is coarser than vellus hair and with the exception of Grey is almost always pigmented
  7. a mature strand of human hair is divided into how many parts
  8. What are the names that the human hair is divided into
    Hair Root and hair shaft
  9. What are the structures of the hair root
    The follicle, bulb, and dermal papilla
  10. What is the follicle
    It is a tube like pockets in the skin or scalp containing the hair root. It surrounds the dermal papilla. Hair follicles are distributed all over the body, with the exception of the palms and soles of the feet
  11. What is the bulb
    The lowest area of the hair strand it is a thickened Club shaped structure that forms the lower part of the hair root. The lower part of the bold fits over and covers
  12. What is the dermal papilla
    A small cone shaped area located at the base of the follicle it contains the blood and nerve supply that provides the nutrients needed for hair growth
  13. What are the structures associated with hair follicles
    Arrector pili and sebaceous glands
  14. What is the arrector pili
    a tiny, involuntary muscle in the base of the hair follicle; strong emotions or cold cause it to contract, which makes the hair stand up straight, resulting in "goosebumps"
  15. What is the sebaceous glands
    the oil glands of the skin connected to the hair follicles; the secrete an oily substance called sebum which lubricates the hair and skin
  16. What oily substance does the sebaceous glands secrete that lubricates the hair and skin
  17. What are the growth patters created by hair follicles
    hair stream- Image Upload 1 

    whorl- Image Upload 2

    cowlick- Image Upload 3
  18. What is a hair stream
    hair that flows in the same direction. Two streams that flow in opposite directions form a natural part in the hair
  19. What is a whorl
    hair that forms a circular pattern, usually on the crown
  20. What is a cowlick
    a tuft of hair that stands straight up
  21. What are the growth cycles of the hair
    Anagen, Catagen, Telogen

    Image Upload 4
  22. What is anagen
    It is the growth phase when new hair is produced. The average growth of healthy hair is about an inch per month. At any one time, about 90% of scalp hair grows in this phase, which generally last from 3-5 yrs. The longer the anagen cycle is, the longer the hair can grow.
  23. What is catagen
    it is the transitional phase after growth during which, the follicle canal shrinks and detaches from the dermal papilla; the hair bulb disappears and the shrunken root end forms a rounded club. At any one time, less than 1% of scalp hair is in this stage, which is very short and lasts from 1-2 weeks
  24. What is telogen
    it is the resting phase and the final phase in the hair cycle, which lasts until the fully grown hair is either shed or is pushed out during the next anagen phase. At any one time, about 10% of the hair is in the is phase which lasts about 3-6 months
  25. On average how long does the entire growth cycle repeat itself
    once every 4 to 5 years
Card Set
Properties of hair and skin.txt
properties of hair and skin