Composition of the lymphatic system DUMMY
Figure 8.17: Diagram of human lymphatic system.The lymphatic system is composed of lymph vessels, lymph ducts, lymph nodes and organs.
The organs associated with the lymphatic system are thespleenandthymus. The spleen is
the boundary between the blood and the lymphatic system. Knots of lymphatic tissue in the
spleen add lymphocytes to the blood. The spleen also acts as a filter for the blood, and helps
to destroy worn out red-blood cells. In the event of damage to the spleen, it can be removed
and its functions will be carried out by the liver, the bone marrow and the lymph nodes.Lymph vesselsare located as a network throughout all tissues in the body. Lymph vessels
assist the circulatory system and all the cells of the body by removing wastes, germs and
excess water from the tissue fluid. Lymph vessels carry lymph fluid from the bottom of the
body up towards the heart and also drains from the head and shoulders as well as the arms.Muscle contractionshelp push the lymph fluid upwards, andvalvesprevent the lymph fluid
from flowing backwards. Many lymph vessels eventually merge into two large lymphatic240 8.3. Lymphatic circulatory system