THE LYMPHATIC SYSTEM
WHAT IS THE LYMPHATIC SYSTEM?
The lymphatic system's anatomy includes the spleen; thymus; lymph nodes and lymph nodules; the lymph capillaries, vessels, trunks, and ducts; the fluid lymph and lymphocytes. It is a one-way system that begins in the tissues and ends when it reaches the blood vessels.
The lymphatic system helps the body maintain homeostasis by collecting accumulated tissue fluid around the cells and returning it to the bloodstream.
The lymphatic system is an open-ended system, beginning in the interstitial spaces. The fluid located around the cells is called interstitial fluid. As fluid pressure increases between the cells, the cells move apart, pulling on the microfilaments that connect the endothelial cells of the lymph capillaries to tissue cells. The pull on the microfilaments causes the lymph capillaries to open like flaps, allowing interstitial fluid to enter the lymph capillaries. The moment interstitial fluid enters a lymph capillary a flap valve prevents it from returning to the interstitial space.
Lymph capillaries join to form larger lymph vessels that resemble veins but have thinner, more transparent walls. Like veins, they have valves to prevent backflow. The large vessels continue to merge and eventually become two main ducts called the right lymphatic duct and the thoracic duct (left lymphatic duct). JUST ABOVE YOUR CLAVICLES/COLLAR BONES.
The right lymphatic duct drains the upper right half of the body and empties into the right subclavian vein. The thoracic duct on the left drains the rest of the body and empties into the left subclavian vein.
The lymph nodes play an active part in the immune defenses of the body by filtering out and destroying foreign substances and microorganisms. Interstitial fluid comes from blood plasma that seeps through capillaries. Interstitial fluid becomes lymph when it moves into the lymph capillaries, which are tiny, open-ended channels located in tissue spaces throughout the body. Lymph contains proteins and other cell by-products, as well as pathogens and cell debris. As lymph travels through lymph vessels, it is filtered by lymph nodes that remove the pathogens and cell debris, before traveling to the bloodstream and once again becoming plasma.
LYMPHATIC CIRCULATION IS SEPARATED INTO TWO LAYERS:
• The superficial circulation, which constitutes 60–70 percent of lymph circulation, is located just under the skin in the junction between the superficial fascia and the dermis. The superficial circulation is not stimulated directly by exercise but is influenced by the stretching and pulling of the skin and superficial fascia during movement.
• Deep muscular and visceral circulation, below the fascia, is activated by muscular contraction, peristalsis, and respiration.
THE MOVEMENT OF LYMPH IS KNOWN AS LYMPHATIC DRAINAGE:
The lymphatic system does not have a central pump like the heart, so various factors assist the transport of lymph through the lymphatic vessels. During inhalation, the thoracic duct is squeezed, which pushes fluid forward and creates a vacuum in the duct. During exhalation, fluid is pulled from the lymphatics into the thoracic duct to fill the partial vacuum. The main mechanism of opening lymph capillary vessels (called collectors) is from the pull of the skin and fascia during movement. Movement of lymph fluid in the lymph vessels is assisted by the pressure exerted by the compression of skeletal muscles against the vessels during physical movement and by changes in internal pressure during respiration. Major lymph plexuses are found on the soles and the palms, possibly because the rhythmic pumping of walking and grasping facilitates lymphatic flow. The lymph vessels themselves may have an intrinsic pumping action.
The focus of the initial pressure and finishing strokes is in the dermis, just below the surface layer of skin, and the layer of tissue just beneath the skin and above the muscles. This is the superficial fascial layer, which contains 60–70 percent of the lymphatic circulation in the extremities. Not much pressure is required to contact the area. If too much pressure is applied, the capillaries are pressed closed; this nullifies any effect on the more superficial vessels.
CONTRAINDICATIONS AND CAUTIONS FOR LYMPHATIC DRAINAGE MASSAGE
If the area in question is swollen, hot, red, and painful, the client should see a medical professional. If inflammation is present, massage the area only after the reason for the condition has been determined.
• Undiagnosed persistent edema should initiate a referral.
• Edematous tissues have poor oxygenation and reduced function, and they heal slowly after injury.
• Chronic edema results in chronic inflammation and fibrosis, which makes the edematous tissue coarse, thicker, and less flexible.
• Massage may lower blood pressure. If the client has low blood pressure, the client may become dizzy upon standing.
FROM:
MASSAGE FOR LYMPHATIC FUNCTION
By Sandy Fritz
MASSAGE AND BODYWORK MAGAZINE JANUARY/FEBRUARY 2016 ARTICLE LIST