Nails and Glands

• Nails


  Hard plates of keratin on the dorsal surface of each distal phalanx
• Sebaceous glands


  Sensitive to hormonal changes - accelerate at puberty
• Inflamed sebaceous glands


  Can result in acne
• Causes of acne


  • Propionibacterium acnes
  • Staphylococcus aureus
• Sweat glands


  Also called sudoriferous glands
• Types of sweat glands

  • Apocrine
  • Merocrine
• Modified sweat glands


  • Mammary glands - secrete milk
  • Ceruminous glands - secrete a waxy substance that combines with sebaceous oils to from earwax
• Skin regeneration


  1. Stem cells of epithelium and connective tissue undergo cell division

  2. Replacing lost or damaged tissue
• Time for skin repair

  Depends on extent of damage
• Four steps of skin repair

  1. Cut blood vessels bleed into the wound

  2. Blood clot forms, and leukocytes clean wound

  3. Blood vessels regrow, and granulation tissue forms

  4. Epithelium regenerates, and connective tissue fibrosis occurs
• Skin repair process


  • Scab formation
  • Tissue granulation
  • Scab removal
  • Scar formation