part_of part of part of only_in_taxon only in taxon Chordata anatomical system hemolymphoid system immune system lymphoid system http://upload.wikimedia.org/wikipedia/commons/b/b3/TE-Lymphatic_system_diagram.svg MIAA:0000197 uberon MAT:0000197 Part of the circulatory system which consists of a series of vessels which collect blood (exclusive of erythrocytes) which seep through capillary walls and return it to the veins.[AAO] Tetrapods have evolved distinct lymphatic systems, in which lymphatic capillaries help drain most of the tissues of the body.[well established][VHOG] TAO:0000385 lymphoid We follow FMA and MA in distinguishing between lymphatic system and lymphoid system, with lymhoid tissue part of the non-lymphatic component, although these terms are often used interchangeably. We assume the ZFA term lymphatic tissue actually corresponds to the broader class (e.g. ZFA lymph node in the ZFA lymphatic system). See tracker for more comments. lymphatic circulatory system EHDAA2:0001043 EHDAA:8677 GAID:931 VHOG:0000842 The lymphatic system in vertebrates is a network of conduits that carry a clear fluid called lymph. It also includes the lymphoid tissue through which the lymph travels. Lymphoid tissue is found in many organs, particularly the lymph nodes, and in the lymphoid follicles associated with the digestive system such as the tonsils. The system also includes all the structures dedicated to the circulation and production of lymphocytes, which includes the spleen, thymus, bone marrow and the lymphoid tissue associated with the digestive system[WP]. XAO:0003199 FMA:74594 lymphatic system EMAPA:37664 The lymphatic systems of reptiles and some birds have lymph hearts, and both groups have extensive lymph vessels, but their functional role in both lymph movement and plasma volume homeostasis is almost completely unknown [10.1152/japplphysiol.00201.2013] ZFA:0000385 lymphatic drainage system UBERON:0002096 Wikipedia:Lymphoid_system NCIT:C12746 systema lymphoideum UMLS:C0024235 MA:0002435 UBERON:0002465 SCTID:362589007 The lymphatic system of anuran amphibians is characterized by large lymphatic sacs and two pairs of lymph hearts that return lymph into the venous circulation but no lymph vessels per se [10.1152/japplphysiol.00201.2013]