Book 4 - Self Instructional Manual for Cancer Registrars - SEER ...

SECTION DTHE LYMPHATIC SYSTEMThe lymphatic system and the cardiovascular system (Section E) together provide the internalenvironment of the body. The blood carries food and oxygen to, and waste products from, the cellsof the body. The lymphatic system consists of a set of vessels and aggregations of lymphatic tissuewhich collect and carry lymph 1 from the body tissues to the veins of the blood circulatory system.Lymph vessels, like blood vessels, are distributed to nearly all parts of the body. The lymphaticsystem carries fluid away from, and not to the tissues; consequently, it is not a continuous closedcirculation system as is the cardiovascular system. The lymph enters the system via the lymphcapillaries and flows into larger and larger collecting vessels until it finally empties into the subclavianveins. Interposed along the lymphatics (lymph vessels) are many lymph nodes, structures which serveas filters to clear the lymph of particulate matter. Lymphatic organs and tissues include lymph nodes,the spleen, thymus, tonsils, and Peyer's patches of the small intestine. The lymph nodes, spleen, andthymus have roles as hematopoietic 2 (lymphopoietic) 3 centers mainly producing lymphocytes.Figure 7. RELATIONSHIP BETWEEN THE BLOOD AND LYMPH CIRCULATORY SYSTEMSArteriaL bLoad from hm&rtV-nou- blood to h-----'T _Lymphandoodo•vmmmetmBLoodvell_t i.O0CoLLmbod¥tissueolBLoodc&p£LL_r£omBLoodartorlotomLymphcap/. ]Ltarlllymph--A clear watery fluid found in the lymph vessels (See page 63 for a more detaileddiscussion.2hematopoiesis--(hemopoiesis)--Formation and development of blood cells.31ymohopoiesis--Formation and development of lymphatic tissue or cells (lymphocytes).53