Chapter 19
Lymphatic System
By Boundless
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The lymphatic structure is based on that of blood vessels.
The lymphatic system comprises a network of conduits called lymphatic vessels that carry lymph unidirectionally towards the heart.
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Lymph circulates to the lymph node via afferent lymphatic vessels and drains into the lymph node in the subcapsular sinus.
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Lymph capillaries are tiny, thin-walled vessels, closed at one end and located in the spaces between cells throughout the body.
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The lymph trunks drain into the lymph ducts, which in turn return lymph to the blood by emptying into the respective subclavian veins.
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A lymphocyte is a type of white blood cell in the vertebrate immune system.
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Lymphoid tissue consists of many organs that play a role in the production and maturation of lymphocytes in the immune response.
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Lymph nodes are small oval-shaped balls of lymphatic tissue distributed widely throughout the body and linked by lymphatic vessels.
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The thymus is a specialized organ that "educates" T cells or T lymphocytes, which are part of the adaptive immune system.
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The spleen, similar to a large lymph node, acts primarily as a blood filter in the mononuclear phagocyte system of the immune system.
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The tonsils are one of the immune system's first lines of defense against ingested or inhaled foreign pathogens.