Topic 4: Integumentary System

• What are the main components of the integumentary system?

  Skin, hair, glands, nails, sensory receptors
• What are the two main parts of the skin?

  The epidermis and the dermis
• What type of tissue composes the epidermis?

  Epithelial tissue
• What is the composition of the dermis?

  Dense irregular connective tissue
• What is located below the dermis?

  The subcutaneous layer (hypodermis)
• What are the layers of thin skin in the epidermis?

  Thin skin has 4 strata or layers:

  -Stratum corneum – most superficial layer

  -Stratum granulosum – keratinocytes undergo apoptosis here (genetic programmed cell death)

  -Stratum spinosum – provides strength & flexibility

  -Stratum basale – deepest layer
• What type of epithelium is the epidermis made of?

  Keratinized stratified squamous epithelium
• What are the four principal types of cells in the epidermis?

  Keratinocytes, melanocytes, immune cells, tactile cells
• What do lamellar granules in keratinocytes secrete?

  A lipid-rich secretion
• What is keratinization?

  Accumulation of keratin in new cells
• What is the function of the papillary layer of the dermis?

  Nourish the epidermis
• What type of connective tissue is found in the papillary layer?

  Aerolar connective tissue
• What are Meissner corpuscles?

  Touch receptors in the dermis
• What is the function of the reticular layer of the dermis?

  Provides strength and flexibility
• What structures are found in the reticular layer of the dermis?

  Adipose cells, hair follicles, nerves
• What are the accessory structures of the skin?

  • Hair
  • Glands
  • Nails
• What is the function of hair?

  Protect the body
• What are the three main parts of a hair?

  Shaft, root, bulb
• What do sebaceous glands produce?

  Sebum
• What is the role of sebum?

  Moistens hair and waterproofs skin
• What do ceruminous glands secrete?

  Cerumen (earwax)
• What are the two types of sudoriferous glands?

  Apocrine and eccrine sweat glands
• What is the function of eccrine sweat glands?

  Secrete sweat to lower body temperature
• What are the principal parts of a nail?

  Nail body, free edge, nail root
• What is the function of the skin in temperature regulation?

  Regulates temperature through sweat and blood flow
• How does the skin protect underlying tissues?

  Keratin protects from microbes and chemicals
• What are cutaneous sensations?

  Touch, pressure, vibration, and pain
• What is the role of vitamin D synthesis in the skin?

  Aids in calcium and phosphorus absorption
• What happens during epidermal wound healing?

  Stratum basale cells reproduce to create new layers
• What occurs during deep wound healing?

  Fibroblasts form scar tissue and replace scab
• What changes occur in the integumentary system with aging?

  Decreased proteins, wrinkles, slower healing
• What is homeostasis?

  Maintaining a stable internal environment
• Why do people sweat when exercising in heat?

  To cool the body through evaporation
• How does the skin respond to a drop in body temperature?

  Inhibits sweating and decreases blood flow
• What causes skin cancer?

  Excessive exposure to the sun
• What are the three common forms of skin cancer?

  Basal cell carcinoma, squamous cell carcinoma, melanoma
• What do UV rays cause?

  Sunburn and skin damage
• What is a burn?

  Tissue damage from heat or chemicals
• What are the three degrees of burns?

  First-degree, second-degree, third-degree
• What characterizes a first-degree burn?

  Damage only to the epidermis