Immune System

• Body systems


  Major systems that work together to enable organisms to function
• There are 11 major body systems
• Body systems don't work in isolation, they are interconnected
• Musculoskeletal system


  Combination of muscular and skeletal systems
• Urinary system


  Part of the excretory system
• Lymphatic system


  Often overlooked or combined with the immune system
• Interstitial fluid


  Fluid found outside of cells, between cells, surrounding cells
• Lymph


  Fluid that doesn't get reabsorbed by blood capillaries and enters the lymphatic system
• Lymph


  • Derived from blood plasma
  • Can contain proteins, lipids, and lipid soluble vitamins
• Lymph movement


  1. Enters lymphatic capillaries

  2. Travels through lymphatic vessels

  3. Drains into lymphatic ducts
• Right lymphatic duct


  Drains lymph from upper right side of body
• Thoracic duct


  Drains lymph from everywhere else in the body
• Lymphatic ducts


  Drain lymph into veins, specifically subclavian veins in the neck
• Lymphatic system works closely with the circulatory system
• Lymphatic system


  • Collects lymph
  • Filters lymph
  • Returns lymph to the blood
• Lymph nodes


  Filter out cellular debris and pathogens from lymph
• Lymph nodes


  • Contain lymphocytes (B and T cells)
  • Contain macrophages
• Swollen lymph nodes can indicate an immune system response to pathogens
• Spleen


  Lymphatic organ that filters blood and contains areas for immune response
• Tonsils


  Lymphatic tissue located where breathing and eating happen, can encounter pathogens
• Primary lymphoid organs


  Bone marrow and thymus, where lymphocytes develop and mature
• Secondary lymphoid organs/tissues


  Lymph nodes, spleen, tonsils, where lymphocytes take action but don't develop
• As people age, the thymus gland shrinks and becomes less active
• Lymphedema


  Swelling caused by compromised lymphatic system function and accumulation of lymph in tissues
• Lymphatic filariasis


  Disease where parasitic nematodes damage the lymphatic system and can cause lymphedema
• Lymphatic filariasis is transmitted by mosquitoes