Human Biology

(Sean Pound) #1

1.62. Lymphatic System http://www.ck12.org


FIGURE 1.122
This diagram shows the parts of the immune system. The immune system
includes several organs and a system of vessels that carry lymph. Lymph
nodes are located along the lymph vessels.

FIGURE 1.123
Each lymph organ has a different job in
the immune system.

Lymphis a yellowish liquid that leaks out of tiny blood vessels into spaces between cells in tissues. Where there is
more inflammation, there is usually more lymph in tissues. This lymph may contain many pathogens.


The lymph that collects in tissues slowly passes into tiny lymph vessels. It then travels from smaller to larger lymph
vessels. Lymph is not pumped through lymph vessels like blood is pumped through blood vessels by the heart.
Instead, muscles around the lymph vessels contract and squeeze the lymph through the vessels. The lymph vessels
also contract to help move the lymph along. The lymph finally reaches the main lymph vessels in the chest. Here,

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