Lymphatic system

• Lymphatic system

  • Plays a significant role in fluid homeostasis, lipid metabolism and immune control
• Lymph vessels

  • Have blind beginnings (lymph capillaries) in the interstitial spaces and contain numerous valves permitting flow TOWARD the heart
  • Form large lymph vessels that eventually reach the vena cava
• Lymph circulation

  Takes place via contractions of the lymph vessels and contractions of muscles that overlie lymph vessels
• Lymph nodes

  • Nodular structures of varying sizes located along the course of lymph vessels
  • Filter the lymph and act as one of the first defences against infection by harbouring lymphocytes and macrophages
  • Infection or inflammation often results in enlarged lymph nodes
• Lymph

  • There is little difference between composition of lymph and interstitial fluid
  • Contains water, numerous lymphocytes, inorganic salts and proteins
• Lymph formation

  Interstitial fluid that DOES NOT re-enter the capillaries is recovered by lymph vessels
• Lacteals

  • Special set of lymph capillaries in small intestinal villi, only found in mammals
  • They are especially important for the transport of dietary lipids