Ch. 6 Hair structure

Card Set Information

Ch. 6 Hair structure
2014-02-15 16:14:42
dermatology exam boerboom cgcc

Structural questions
Show Answers:

  1. Pilus
    Another name for hair
  2. What is hair?
    a slender filament of keratinized cells that grows from a tube in the skin called a hair follicle
  3. Hair is found everywhere on the body except some places:
    palms and soles, ventral and lateral surfaces of fingers and toes, lips, nipples
  4. Bulb: a swelling at the base where hair originates in dermis or hypodermis

    • Only living hair cells are in or
    • near bulb
  5. Root: the remainder of the hair in the follicle
  6. Root: the remainder of the hair in the follicle
  7. Where does a hair bulb grow?
    Around a dermal papilla. The papilla is vascular so it nourishes the hair
  8. What is the hairs growth center called?
    • Hair matrix, located directly above the papilla and is the region of mitotically active cells
  9. Hair receptors: entwines the follicle and respond to movements. run your hand over your arm hairs without touching skin
  10. Arector pili muscle: Stands the hair up when stimulated by things like fear or cold. made of smooth muscle cells
  11. Two layers on the inside of the hair
    Medulla (inner region), and the cortex (outside region)
  12. The two sheaths of the root
    • Epithelial root sheath: extension of epidermis, lines the root directly. forms a bulge toward the deep part for stem cells

    Connective tissue root sheath: Surrounds ERS, is more dense than the surrounding connective tissue. Derived from the dermis
  13. Hair functions
    •Hair receptors alert us of parasites crawling on skin

    •Scalp has hair that is thick enough to help us retain heat and protect against sunburn

    –Brain receives a rich supply of warm blood and most of scalp lacks an insulating fat layer

    –Heat is easily conducted through the bones of the skull and lost to surrounding air – hair helps prevent this

    •Pubic and axillary hair signify sexual maturity

    • •Guard hairs which protect nostrils and ear
    • canals