ANATOMY OF LYMPHATICS
(made simple)

The Interstitium is the empty space under the skin, above the muscles, and between the vessels. Within the interstitium are the blood capillaries and initial lymphatics coming together to begin the journey of the fluids (no longer needed for cell nutrition) back to the heart.

The blood capillaries of the venous system cannot transport the heavier protein cells, dead cells (debris), bacteria, and other waste products. This is the job for the initial lymphatics – to take up these heavier fluids and send them on to the larger collector vessels, on to the nodes (where lymph is filtered and lymphocytes are produced and stored for entrance into the bloodstream to fight antigens and bacteria) and more vessels and more nodes until lymph reaches the deep lymphatic vessels of the cistera chylli and abdominal region, and finally to the Major Lymphatic Ducts (Thoracic duct and Right Lymphatic Duct) that return the lymph fluids to the heart where all fluids are then circulated for oxygenation and pumped back out to the body through the arterial system:
initial lymphatics → collector vessels → nodes → more vessels and nodes → deep lymphatic vessels → Major Lymphatic Ducts → heart

What mechanism encourages the take-up of lymph by the initial lymphatics, vessels without valve structures to pump? The lymph moves by “force pump”, a sensitivity to change in pressure. Needed changes in pressure occur with:
       1.) movement
       2.) muscle work (working pressure),
       3.) external pressure (resting pressure)
       4.) respiration (breathing changes thoracic pressure).

A directional light massage technique called Manual Lymph Drainage is used in treatment of lymphedema to stimulate and direct the flow of lymph fluids. All management techniques learned in therapy are based on these four ways to stimulate lymphatic flow.

The lymphatic System is similar to the roadways of a town. The fluid flow back to the main vessels that lead to the heart is like cars moving along the country roads on their way to the interstate (the nodes and vessels of the axilla [arm pit]). With compromise from surgery and radiation the interstate is closed, traffic jams are forming. The traffic backs up until the byways leading to the main thoroughfare become crowded and jammed. Detours must be found. The job of the physical therapist lymphedema specialist is to help create the detours, to bring the natural lymph flow of the body back into gear, to direct the lymph around the compromised area and over to healthy areas that can function to redirect the “traffic” and unblock the stagnant fluids in the limb. All components of the self-management program (wrapping, compression garments, self-massage, aerobic, stretching, breathing, and strengthening exercises) are designed to encourage lymphatic flow, as well.

Copyright Idelle Packer, 2006