Unlike blood vessels that circulate blood in a continuous, closed-loop system, lymphatics carry fluid in one direction.
The lymphatic pathway begins with lymph capillaries, the smallest key in of vessel.
Lymph capillaries are made up of a single layer of overlapping cells.
myboxpra / iStock / Getty Images
This arrangement allows fluid to flow into the vessel but not out.
Lymph capillaries merge to form progressively larger lymphatic vessels.
The largest of these are lymphatic trunks and ducts.
Ultimately, the lymphatic vessels feed into the subclavian vein, returning the fluid to the blood.
Along the way, the lymphatic vessels pass lymph throughlymph nodes for filtration.
A layer of smooth muscle surrounds lymphatic vessels.
As this muscle contracts, it propels the lymph forward.
Lymphatic vessels also contain valves that prevent backflow.
Clusters of lymph nodes are found in the armpit, groin, and neck.
Anatomical Variations
Certain congenital disorders can affect the normal development of lymphatic vessels.
As such, lymphedema (swelling), particularly in the legs and feet, can develop.
Individuals affected with this disorder are also at increased risk of cellulitis, a punch in of skin infection.
Individuals with lung issues may cough and have difficulty breathing.
When lymphangiomatosis affects the bone, fractures and pain can occur.
The severity of the disease can range from asymptomatic or mild symptoms to severe impairment and even death.
The fluid located around the cells is called interstitial fluid.
This fluid delivers oxygen and nutrients to the cells.
Most of the fluid flows back into the bloodstream, but some is left behind.
The remaining fluid is taken up by lymphatic capillaries and is now referred to as lymph.
The lymphatic system transports the lymph and delivers it back into the blood circulation at the subclavian vein.
This balance of fluid is vital.
Fat Absorption
The absorption of nutrients from the digestive tract happens in the small intestine.
The lining of the small intestine is covered with hair-like projections called villi.
In the center of each villus, there are blood and lymphatic capillaries.
Blood capillaries are responsible for most nutrient absorption.
Lymph nodes are responsible for filtering the lymph and killing any microorganisms ordamaged (potentially cancerous) cells.
Lymph nodes contain immune cells such as lymphocytes.
This activation of lymphocytes is responsible for the swollen lymph nodes you may experience during an illness.
Associated Conditions
Here are some issues that are directly related to problems with the lymphatic system.
Lymphedema
Lymphedema describes the buildup of fluid within tissues due to insufficient lymph transport.
Swelling usually happens in the arms or legs but can also occur in other body parts.
The resulting lymphedema can be mild or severe.
Affected areas are also more prone to infections and sores.
Lymphedemais a common complication after breast cancer treatment.
Treatment often involves the surgical removal of lymph nodes under the arm and radiation.
Arm swelling develops where the lymph nodes were removed.
Early diagnosis is crucial to preventlymphedemafrom getting worse.
These cancerous cells are taken up andtransported by the lymphatic system.
Secondary tumors are responsible for 90% of cancer deaths.
Once diagnosed, you’re able to move forward with treatment to improve your quality of life.
National Cancer Institute.Components of the lymphatic system.
Lymphangiomatosis & Gorham’s Disease Alliance.What is lymphangiomatosis?
National Cancer Institute.Introduction to the lymphatic system.
Centers for Disease Control and Prevention.Lymphedema.
Moore JE Jr, Bertram CD.Lymphatic system flows.Annu Rev Fluid Mech.
2018;50:459-482. doi:10.1146/annurev-fluid-122316-045259
Munn LL, Padera TP.Imaging the lymphatic system.Microvasc Res.
