Developmental Aspects of Skin and Body Membranes

• Lanugo


  a downy hair, covers the body by the fifth or sixth month of fetal development but disappears by birth

  
• Vernix caseosa


  an oily covering, is apparent at birth

  
• Milia


  small white spots, are common at birth and disappear by the third week

  
• Acne


  may appear during adolescence

  
• Pimples, scales, and dermatitis


  more common with aging skin
• In youth


  skin is thick, resilient, and well hydrated
• With aging

  skin loses elasticity and thins

  
• Skin cancer


  a major threat to skin exposed to excessive

  
• Balding(alopecia)


  graying occurs with aging; both are genetically determined; other factors that may contribute include drugs and emotional stress