Japanese Journal of Veterinary Research;Volume 7, Number 1-4



SUGIMURA, Makoto;KUDO, Norio;TAKAHATA, Kurahiko

Permalink : http://hdl.handle.net/2115/4648
JaLCDOI : 10.14943/jjvr.7.1-4.27


The results of the already published three reports and this paper are summarized as follows (ref. the summarized table) : 1. The 48 groups of lymph nodes were distinguished by their positions in the cat. Out of them, 9 groups : Lnn. subinguinales profundi, Lnn. epigastrici craniales, Ln. femoralis lateralis, Ln. prefemoralis, Lnn. intestinales, Lnn. sacrales laterales, Ln. mediastinalis ventralis, Lnn. mediastinales dorsales and Ln. diaphragmaticus, as lymph nodes in the cat, are herein described for the first time on the basis of the writers' observations. Furthermore, in 13 groups (^* mark) some revisions have become necessary in detailed descriptions. 2. Each group of lymph nodes was placed in either the constant (100%), nearly constant (less than 100%, over 80%) or inconstant (less than 80%) group determined by that occurrence ratio. The inconstant group, it showed a specific feature in that it consists of small nodes, generally less than 6mm in the longest diameter. 3. In regard to the numbers of lymph nodes, some remarkable individual variations were noted in the abdominal cavity only, but not in other areas. No definite variations were found by sexes or between the right and left sides of the body. 4. The afferent and efferent lymphatic vessels of the above groups of lymph nodes have been described in the writers' series of reports. 5. In addition, three kinds of specific lymph streams were distinguished and discussed, as follows : 1) The branch lymph streams of the thoracic duct and jugular trunks were detected in some cases. Some branches of the thoracic duct passed through Lnn. mediastinales craniales, Lnn. tracheobronchiales craniales dextri, as has already been stated in respect to the cat. The writers, furthermore, found for the first time some branches of the thoracic duct which passed through Lnn. mediastinales dorsales, Lnn. tracheobronchiales craniales sinistri, Lnn. tracheobronchiales caudales and Ln. infraclacicularis, and some branches of the jugular trunk which passed through Lnn. anguli brachiocephalici. In the thoracic duct of the cat, the network formation surrounded Aa. intercostales in all cases. 2) Some peripheral lymphatic vessels, originating from the trachea, esophagus, thyroid gland, thymus, diaphragm, costal pleura, testis and ovary, empty directly into the jugular trunk, thoracic duct, lumbar trunk or cisterna chyli without the lymph passing through a node and then pour into the venous angles. The appearance of such lymphatic vessels is related intimately with the degree of occurrence of the special fixed nodes in accordance with the peripheral areas of their origin. It was suggested that such lymphatic vessels maintain an undifferentiated state without developing any appropriate node. 3) The writers found lymphatic communications by which lymph streams reversely among lymph nodes. The communications are divided into three types as follows : type A-connection by which lymph is able to stream reversely through a valveless-like vessel; type B-connection whose lymphatic vessels with single flowing direction alternate with each other among nodes; type C-connection by lymphatic networks with valves at various places. To the matter of this finding, no attention has been paid particularly until now. The occurrences of such communications are more numerous in the body surface than those in the thoracic and abdominal cavities. From the obtained results and from consideration of the development of the lymphatics, it seems that such communications derive from a remainder of a lymphatic plexus which appeared in the course of the developmental process. The third type is C, an original form, which may be changed from type B to type A, a more advanced one. A lymph stream by way of such communications among nodes may flow from the periphery towards the body center in the normal living state. But if the tissue pressure in the peripheral areas is made higher by some conditions, such flow can clearly be reversed. The three kinds of specific lymph vessels should be noted in pathology and physiology to act as a specific pathway of the lymph. 6. The writers divided lymph nodes into three types of Z, T and ZT, and made macroscopic observations with considerations of the structural differences among the nodes of each type. The node of type Z receives only peripheral lymph, that of type T receives only lymph which has passed through other nodes and that of type ZT receives both sorts of lymph. The occurrences of each type differed among the groups of lymph nodes which were determined by their locations. As a rule, no definite differences were macroscopically detected between types Z and ZT, but only type T showed a specific feature; type T is small node, approximately 1mm in diameter, which does not join into groups at a definite position but appears as an accessory one accompanying types Z and ZT without exception. 7. From the ratio of occurrences, types classified by appearances of afferent vessels and sizes of lymph nodes, the writers suggest, at least, that there is something of structural difference among nodes of 3 groups as follows : 1. nodes of types Z and ZT in the writers' constant and nearly constant groups, 2. nodes of types Z and ZT in the writers' inconstant group, 3. nodes of type T, without falling into groups classified with relation to their ratio of occurrence. The suggestion should be followed up by microscopical observations. 8. In this observation, Neoprene latex was used in an attempt to find whether it was applicable for demonstration of lymphatic vessels. Neoprene latex is within the range of possibility of use as an injection material for comparatively larger vessels, but more advanced study is necessary before it can be recommended for injection into the peripheral lymphatic vessels.