Anatomy and Physiology: The Lymphatic System

Lymphatic System Structure and Function

Lymphatic system

The lymphatic system drains away excess fluid that does not return to the blood capillaries; absorbs fats from the small intestine and protects against foreign invaders.

Structure of the lymphatic system:

  • Capillaries – function – allows for easy passage of soluble materials and water
  • Lymphatic vessels – function – to carry lymph
    • Superficial vessels – small vessels near superficial veins immediately below the skin
    • Deep vessels – larges vessels near deep veins
      • Lymphatic tissues – function – removal of impurities and processing cells which combat infection and fight foreign invaders
        • Lymph nodes – filters lymph once it is drained from the tissues
        • Tonsils – filters tissue fluids
        • Thymus – development of immune system before birth and the first few months of infancy.
        • Spleen – filters blood, destructs old red blood cells, produces red cells before birth, stores blood
  • Right lymphatic duct – function – drains upper right part of the body and empties into right subclavian vein
  • Thoracic duct – function – drains remainder of body and empties into left subclavian vein