integumentary system

integumentary system

1. consists of:

   • skin: as an Organ
     • -Epidermis
     • -Dermis
   • skin: as a system
     • accessory structures:
       • skin appendages

2. Function

   • protection
     • -Against physical, chemical ,and biological
   • sensation
     • -contains sensory receptors (Pain and Touch)
       • -Associated with nerve endings
   • Temperature Regulation
     • -through sweating and shivering
       • regulation of skin blood flow (negative feedback)
   • Vitamin D production and Metabolism
   • Excretion
     • -Of salts and wastes such as (ammonia and Urea)

3. skin / Integument

4. skin (Integument)

   • our largest organ which accounts for 7% of the body weight
     • -Hypodermis which lies deep to the dermis but NOT PART OF THE SKIN

5. Epidermis

   • consists of FOUR main cell types
     • 1-keratinocytes
       • -Most abundant cell in Epidermis
       • -Arise from deepest layer
       • -Produce protein keratin (a tough fibrous protein)
       • -Produce antibodies and Enzymes
       • -Keratinocytes are dead at the skin surface
     • 2-Merkel cells
       • serve as a sensory function (Detect light touch and pressure)
     • 3-langerhans cells (Epidermal dendritic cells)
       • Phagocytic cells-part of the immune system
     • 4-Merkel cells
       • Produce pigment Melanin
         • -Contribute to skin color
         • -Protect against UV sun radiation

6. Epidermal layers

   • 1-stratum corneum
   • 2-stratum luicidum
   • 3-stratum Granulosum
   • 4-stratum spinosum
   • 5-stratum basale