integ notes

• integumentary system

  • provide protective two-way barrier between internal and external environment
  • temperature regulation
  • houses sensory receptors
  • secretes important fluids
• skin is the largest external body organ
• epidermis


  squamous cell epithelium

  does not have blood supply or any connective tissue
• basal layer


  deepest layer of the epidermis

  contains special cell called melanocytes
• melanocyte


  produce the black pigmentation
• pigmentation


  responsible for skin color and protects against UV rays
• dermis 


  true skin, corium

  deepest layer of the skin living tissue with an excellent blood supply
• collagen fibers


  made from a strong, fibrous protein present in connective tissue, forming a flexible glue that gives connective tissue its strength
• subcutaneous layer


  hypodermis

  separates the dermis from deeper tissues.
• lipocytes


  fat cells

  protects deeper tissues of the body from trauma

  acting as insulation from heat and cold

  serves as a source of energy in a starvation situation
• cili/o, pil/o


  made up of protein keratin fibers
• hair root


  force older keratinized cells to move upward
• hair shaft


  grows toward the skin surface within the hair follicle
• sebaceous gland


  release oil directly into the hair follicle
• arrector pili


  smooth muscle

  causes hair shaft to stand up resulting to goose bumps
• ungual


  flat plate of keratin called the nail body that covers the top end of the fingers and toes
• free edge


  exposed edge
• lunula


  light-color half- moon area at the base of the nail
• sebacceous glands


  secrete the oil sebum, which lubricates the hair and skin
• sweat glands


  sudoriferous glands

  located in the dermis
• sweat ducts


  where sweat travels
• sweat pores


  surface opening of sweat duct
• apocrine glands

  secretes thicker sweat

  produce odor when in contact with bacteria