Final answer:
Lymph is the interstitial fluid that is collected into lymphatic capillaries, transported through the lymphatic vessels, filtered through lymph nodes, and eventually drained back into the bloodstream.
Step-by-step explanation:
Lymph is the name of the interstitial fluid that has entered a lymphatic capillary. Small lymph capillaries interact with the blood capillaries, allowing excess fluid and larger molecules, including white blood cells, to enter from the interstitial spaces, thus forming lymph. This circulatory process plays a vital role in maintaining the body's fluid balance and in the immune system.
The lymphatic vessel serves as a conduit for the lymph, transporting it to larger lymphatic ducts and finally draining it back into the bloodstream. Along the way, lymph passes through lymph nodes where pathogens are filtered out and destroyed, ensuring that the lymph returned to the circulation is cleansed. Unlike the blood circulatory system, the lymphatic system does not have a central pump; instead, lymph movement relies on skeletal muscle action and the contractions of the lymphatic vessels themselves.