integumentary system

• What organs are included in the integumentary system?

  Skin and its accessory structures
• What is dermatology?

  Medical specialty for skin disorders
• What is the largest organ of the body?

  The skin
• How much does the skin weigh?

  4.5-5 kg (10-11 lb)
• What is the average thickness of the skin?

  1 – 2 mm
• What are the two major layers of the skin?

  Epidermis and dermis
• What is the subcutaneous layer also called?

  Hypodermis
• What type of tissue is the epidermis made of?

  Epithelial tissue
• What is the primary cell type in the epidermis?

  Keratinocytes
• What do keratinocytes produce?

  Keratin
• What is the function of melanocytes?

  Produce melanin to protect against UV damage
• What do Langerhans cells do?

  Involved in immune responses
• What is the function of Merkel cells?

  Sensation of touch
• How many layers does thin skin have?

  Four major layers
• What is the deepest layer of the epidermis called?

  Stratum Basale
• What occurs in the Stratum Basale?

  Continuous cell division
• What is the function of the Stratum Corneum?

  Protects from abrasions and pathogens
• What is the role of the dermis?

  Support and protect the skin
• What type of tissue is the dermis composed of?

  Connective tissue
• What are the two layers of the dermis?

  Papillary and reticular layers
• What does the papillary region of the dermis consist of?

  Areal connective tissue
• What is the role of melanin in skin color?

  Absorbs UV radiation
• What is a nevus?

  A benign overgrowth of melanocytes
• What is albinism?

  Inability to produce melanin
• What pigment gives skin a yellow-orange color?

  Carotene
• What is the function of sebaceous glands?

  Secrete sebum to prevent dehydration
• What are the two types of sweat glands?

  Eccrine and apocrine glands
• What are nails composed of?

  Hard, keratinized epidermal cells
• What is the function of the skin?

  Regulation of body temperature
• What happens to the skin as a person ages?

  Wrinkling and decreased immune responsiveness
• What are the functions of the skin?

  • Regulation of body temperature
  • Blood reservoir
  • Protection
  • Cutaneous sensations
  • Excretion and absorption
  • Synthesis of vitamin D
• What are the components of hair?

  • Shaft: projects above skin
  • Root: penetrates into the dermis
  • Hair follicle
  • Epithelial root sheath (internal)
  • Dermal root sheath (external)
• What are the components of nails?

  • Free edge
  • Transparent nail body (plate)
  • Whitish lunula at base
  • Nail root embedded in skin fold
• What changes occur in the skin with aging?

  • Wrinkling
  • Decreased immune responsiveness
  • Dehydration and cracking
  • Decreased sweat production
  • Loss of subcutaneous fat
  • Increased susceptibility to conditions