Table of ContentsView AllTable of ContentsAnatomyFunctionAssociated ConditionsTests
Table of ContentsView All
View All
Table of Contents
Anatomy
Function
Associated Conditions
Tests
Lymphatic vessels (also known as lymph vessels or lymphatics) are part of the body’slymphatic system. The lymphatic system also includes lymph (the fluid found within the vessels) and lymphatic organs, such aslymph nodes.
Together with the rest of the system, lymphatic vessels help maintain the body’s fluid balance, absorb fats from the digestive tract, and provide immune defense against microorganisms and disease.Impairment in these functions can cause issues like lymphedema and thespread of cancer cells.
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Here’s a breakdown of how the lymphatic vessels are set up as part of the total lymphatic system.
Structure
Lymphatic vessels are tube-like structures that carry fluid (called lymph) away from the tissues to deliver it back into the blood’s circulation. 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 type of vessel. Lymph capillaries are made up of a single layer of overlapping cells. 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.
Location
Anatomical Variations
Certain congenital disorders can affect the normal development of lymphatic vessels.
Lymphangiomatosis describes the abnormal overgrowth of lymphatic vessels.This condition can affect one or multiple organs and usually impacts the lungs and bones. 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 primary functions of the lymphatic vessels and system include:
Fluid Balance
As blood circulates, fluid leaks out of blood capillaries and surrounds tissue cells. The fluid located around the cells is called interstitial fluid. This fluid delivers oxygen and nutrients to the cells.
The lymphatic system transports the lymph and delivers it back into the blood circulation at the subclavian vein. This balance of fluid is vital. Removing interstitial fluid at the same rate it is produced helps maintain blood pressure and prevent edema (swelling in the tissues).
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. However, specialized lymphatic capillaries, called lacteals, absorb fats and fat-soluble vitamins (vitamins A, D, E, and K). Once absorbed, the fats and vitamins make their way through the lymphatic system and are delivered to the bloodstream.
Immune Functions
As lymph travels along the lymphatic pathway, it passes through bean-shaped structures called lymph nodes. Lymph nodes are responsible for filtering the lymph and killing any microorganisms ordamaged (potentially cancerous) cells.
Lymph nodes contain immune cells such as lymphocytes. When a microorganism is detected in the lymph, lymphocytes multiply and travel to the infection site to help destroy the invading agent. This activation of lymphocytes is responsible for the swollen lymph nodes you may experience during an illness.
How to Give Yourself a Lymphatic Drainage Self-Massage
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.
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.
Spread of Malignant Tumors
Secondary tumors are responsible for 90% of cancer deaths.
Imaging tests used to visualize the lymphatic system can help:
Some imaging tests include:
Diagnosing lymphedema may also involve a computed tomography (CT) scan or doppler ultrasound.These tests can identify obstructions and rule out other causes of swelling, such as a blood clot.
Based on your risk factors for lymphedema, your healthcare provider may be able to make a diagnosis with a physical exam alone. Once diagnosed, you can move forward with treatment to improve your quality of life.
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Cleveland Clinic.Lymphatic system.National Cancer Institute.Components of the lymphatic system.MedlinePlus.Milroy disease.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-122316-045259Munn LL, Padera TP.Imaging the lymphatic system.Microvasc Res. 2014;96:55-63. doi:10.1016/j.mvr.2014.06.006
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Cleveland Clinic.Lymphatic system.National Cancer Institute.Components of the lymphatic system.MedlinePlus.Milroy disease.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-122316-045259Munn LL, Padera TP.Imaging the lymphatic system.Microvasc Res. 2014;96:55-63. doi:10.1016/j.mvr.2014.06.006
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Cleveland Clinic.Lymphatic system.National Cancer Institute.Components of the lymphatic system.MedlinePlus.Milroy disease.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-122316-045259Munn LL, Padera TP.Imaging the lymphatic system.Microvasc Res. 2014;96:55-63. doi:10.1016/j.mvr.2014.06.006
Cleveland Clinic.Lymphatic system.
National Cancer Institute.Components of the lymphatic system.
MedlinePlus.Milroy disease.
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. 2014;96:55-63. doi:10.1016/j.mvr.2014.06.006
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