Any routine visit to the physician includes the familiar cold-hands-­under-the-earlobes lymph node check. But how often do you think about what the doctor is checking for or how important the lymphatic system is? And have you told your clients that physical activity plays a key role in supporting this crucial ­system?

An essential part of immunity, the lymphatic system is similar to the circulatory system in that it has a wide network of vessels that spans bodily tissues, enabling lymph fluid to move. Lymph, the clear fluid derived from blood plasma, drains through lymphatic vessels in much the same way as blood returns to the heart via veins (MacGill 2016). The lymphatic system includes lymph vessels, lymph nodes and lymphoid tissues (National Lymphedema Network 2018). It has three primary jobs: to maintain fluid balance, to work with the immune system, and to help with the absorption of fats and fat-soluble nutrients (MacGill 2016). Here are more facts to share with your clients and class attendees:

  • The lymphatic system doesn’t have a “pump,” which is one reason why regular movement is so important. When we squeeze our muscles, lymph fluid moves through the vessels and “is pushed back from the peripheries to the center” (MacGill 2016).
  • Researchers who studied patients with lymphedema found that even short bouts of exercise—2 minutes—significantly improved lymph system drainage (Tartaglione et al. 2010).
  • There may be as many as 700 nodes in the human body that filter lymph fluid before it returns to the circulatory system ( 2014).
  • The largest lymphatic system organ is the spleen ( 2014); however, the spleen doesn’t filter lymph (MacGill 2016). Other lymphatic tissues include the tonsils and the thymus gland.
  • Unlike blood, lymph fluid flows in only one direction—up toward the neck
    ( 2014).
  • Thomas Bartholin, a doctor from Denmark, was the first person to describe the lymphatic system. He published his study around 1652 ( 2018).