Integumentary system

• the main function of our integumentary system

  1. storing of blood
  2. excretion and absorption
  3. protection
  4. thermoregulation
  5. sensory reception
  6. vitamin D synthesis
• Our skin consists of 3 main layers: the epidermis, dermis, and hypodermis, or the subcutaneous layer.
• The integumentary includes skin, hair, oil and sweat glands, nails, and sensory receptors.
• Epidermis is made of keratinized stratified squamous epithelium, located at the top of our skin.
• The dermis is a type of connective tissue, which is a non-epidermal type of tissue that connects things together in the body.
• The dermis has fibers of two types of proteins: collagen– providing support and elastin – which gives it elasticity. These proteins are made by specialized cells in this layer called fibroblasts.
• Now the last layer, the hypodermis (hypo = below), or subcutaneous layer, is a distinct layer beneath the skin
• HYPODERMIS: This layer stores most of the body’s fat, providing insulation, energy reserves, and shock absorption to protect muscles, bones, and organs. Fibers from the dermis anchor the skin to the hypodermis, which connects to the fascia surrounding muscles and bones. Although anatomically separate, the hypodermis closely collaborates with the skin to provide insulation, temperature regulation, and structural support.
• eccrine - produces watery glands
• apocrine - produces thicker fluid
• sebaceous - produces sebum for lubrication
• ceruminous - produces earwax
• dermis has two types of protein: collagen and elastin
• collagen - for support
• elastin - provides elasticity
• dermis has two general layers: papillary layer and deeper reticular layer
• collagen and elastin are made by specialized cells called fibroblasts
• epidermis' 4 principal cell types:

  melanocytes

  merkel

  langerhans

  keratinocytes
• melanocytes - produces melanin
• merkel - sensory functions
• langerhans - immune defense
• keratinocytes - keratin