lymphatic vessel

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Diagram of the human lymphatic system highlighting lymphatic vessels and major lymphoid organs, including lymph nodes, adenoids, tonsils, thymus gland, spleen, appendix, bone marrow, and ducts.

Examples of extracellular fluids include lymph and plasma.

lymphatic vessel

anatomy

Also known as: lymph vessel

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June 30, 2026

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Diagram of the human lymphatic system highlighting lymphatic vessels and major lymphoid organs, including lymph nodes, adenoids, tonsils, thymus gland, spleen, appendix, bone marrow, and ducts. — Diagram of the human lymphatic system The human lymphatic system, showing the lymphatic vessels and lymphoid organs.

The lymphatic system is a network of vessels, tissues, and organs that works alongside the circulatory system. Its primary role is to maintain fluid balance by collecting excess fluid and waste materials from tissues and returning them to the bloodstream. This fluid, known as lymph, contains lymphocytes, which are crucial for the body's immune defense against infection.12

Lymphatic vessels permeate almost every tissue, collecting interstitial fluid that leaks from blood capillaries. This fluid, along with proteins and other substances too large to re-enter blood capillaries, is transported through the lymphatic vessels. The flow of lymph is aided by muscle contractions and is regulated by valves that prevent backflow. Along the way, lymph is filtered through lymph nodes, which trap foreign materials like microorganisms. The lymphatic system is essential for preventing fluid buildup in tissues and plays a vital role in immunity by producing and transporting disease-fighting cells.231

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prenatal development
Lymphatic vessels
The lymph vessels develop independently in close association with the veins. Linkages produce the thoracic duct, which is the main drainage return for lymph. Masses of lymphocytes accumulate about lymphatic vessels and organize as lymph nodes. The spleen has somewhat similar tissue, but its channels are…
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The lymph vessels develop independently in close association with the veins. Linkages produce the thoracic duct, which is the main drainage return for lymph. Masses of lymphocytes accumulate about lymphatic vessels and organize as lymph nodes. The spleen has somewhat similar tissue, but its channels are…
Read More

human respiratory system
Blood vessels, lymphatic vessels, and nerves
…distinct but interconnected sets of lymphatic vessels. The superficial, subpleural lymphatic network collects the lymph from the peripheral mantle of lung tissue and drains it partly along the veins toward the hilum. The deep lymphatic system originates around the conductive airways and arteries and converges into vessels that mostly follow…
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…distinct but interconnected sets of lymphatic vessels. The superficial, subpleural lymphatic network collects the lymph from the peripheral mantle of lung tissue and drains it partly along the veins toward the hilum. The deep lymphatic system originates around the conductive airways and arteries and converges into vessels that mostly follow…
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lymph
…the venous bloodstream via the lymphatic vessels. On the way, it is filtered through the lymphatic organs (spleen and thymus) and lymph nodes.
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…the venous bloodstream via the lymphatic vessels. On the way, it is filtered through the lymphatic organs (spleen and thymus) and lymph nodes.
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lymph node
…cells enter through the afferent lymphatic vessels, which drain into each node through its convex surface. These vessels may drain directly from the lymphatic capillaries, or they may be connected to a previous node. Lymphocytes generally enter through specialized blood vessels called high endothelial venules (HEVs). HEVs contain a single…
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…cells enter through the afferent lymphatic vessels, which drain into each node through its convex surface. These vessels may drain directly from the lymphatic capillaries, or they may be connected to a previous node. Lymphocytes generally enter through specialized blood vessels called high endothelial venules (HEVs). HEVs contain a single…
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trachea
…there are numerous blood and lymphatic vessels; the blood vessels control cellular maintenance and heat exchange, while the lymphatic vessels remove the foreign particles collected by the wall’s surface. Around the tracheal wall there is a series of 16 to 20 horseshoe-shaped cartilage rings. They encircle the front part of…
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…there are numerous blood and lymphatic vessels; the blood vessels control cellular maintenance and heat exchange, while the lymphatic vessels remove the foreign particles collected by the wall’s surface. Around the tracheal wall there is a series of 16 to 20 horseshoe-shaped cartilage rings. They encircle the front part of…
Read More