Integumentary system

• What is the outer layer of the body called?

  integumentary system
• What organs are included in the integumentary system?

  Skin, hair, nails, glands
• What is the primary function of the integumentary system?

  Acts as a physical barrier, protecting the body from various threats, such as bacteria and infection
• What is the largest organ in the body?

  Skin
• How thick is the skin?

  0.5-4 mm thick
• Why is skin thicker on the soles of the feet?

  It endures more stress and pressure
• What are the three layers of the skin?

  • Epidermis
  • Dermis
  • Hypodermis
• What is the primary cell type in the epidermis?

  Keratinocytes
• What do keratinocytes produce?

  Keratin, a protective fibrous protein
• What is the role of melanocytes?

  Produce melanin to protect against UV damage and provides skin with colour
• What type of cells are Langerhans cells?

  Involved in immune responses
• What do Merkel cells function in?

  Sensation of touch
• What are the layers of the epidermis?

  1. Stratum basale
  2. Stratum spinosum
  3. Stratum granulosum
  4. Stratum lucidium (only in thick skin)
  5. Stratum corneum
• What occurs in the stratum basale?

  Continuous cell division produces new skin cells
• How many layers are in the stratum spinosum?

  8-10 layers of keratinocytes
• What is the function of the stratum granulosum?

  Includes keratohyalin and lamellar granules for skin strength
• What is unique about the stratum lucidium?

  It is only found in thick skin to reduce friction between above and below layers
• What happens to keratinocytes in the stratum corneum?

  They become corneocytes, providing protection
• What is the structure and function of the dermis?

  • Composed of collagen and elastic tissue
  • Supports and protects the skin
  • Assists in thermoregulation
  • Aids in sensation
• What are the two layers of the dermis?

  Reticular dermis and papillary dermis
• What does the reticular dermis contain?

  Blood vessels, connective tissue, hair follicles, and sweat glands
• What is the function of the papillary dermis?

  Contains nerve endings and supports the epidermis
• What are the functions of the hypodermis?

  • Stores energy
  • Insulates the body
  • Protects muscles and bones
  • Connects skin to underlying organs, muscles, and bones
• What causes variations in skin color?

  Variations in amount of melanin, carotene, and haemoglobin
• What is a nevus?

  A benign overgrowth of melanocytes
• What is albinism?

  An inherited inability to produce melanin
• What is vitiligo?

  Partial or complete loss of melanocytes
• What are the functions of hair?

  • Protection from debris - eyelashes and eyebrows protect eyes
  • Reduces heat loss
  • Senses light touch
• What is the hair shaft?

  The visible part of the hair
• What is the role of the hair follicle?

  Keeps hair anchored in the skin
• What determines hair color?

  Amount of melanin, carotene, and blood
• What are the types of skin glands?

  • Sebaceous glands
  • Sudoriferous (sweat) glands
  • Ceruminous glands
  • Mammary glands
• What do sebaceous glands secrete?

  Sebum, which prevents dehydration of hair and skin
• What do eccrine glands do?

  Produce sweat to regulate body temperature
• Where are apocrine glands primarily found?

  In the armpits and groin
• What do ceruminous glands produce?

  Ear wax
• What do mammary glands produce?

  Milk
• What are the functions of nails?

  • Protect ends of fingers and toes
  • Composed of hard, keratinized cells
• What is the free edge of a nail?

  The transparent part of the nail
• What is the lunula of a nail?

  The white, moon-shaped part