Final answer:
External genitalia pathologies generally spread first to the superficial inguinal lymph nodes, while pathologies from the gonads drain into the para-aortic lymph nodes. Lymph nodes filter lymph fluid, trapping pathogens. Lymphogranuloma venereum is an example of disease spread through lymph nodes in the groin area.
Step-by-step explanation:
The major lymph node groups that can be involved in the spread of pathology from the external genitalia and the gonads include different nodes for each region. For the external genitalia, the first palpable group of lymph nodes are the superficial inguinal lymph nodes. Pathology from the gonads, particularly the testes, typically drains into the para-aortic lymph nodes which would be the first palpable group in cases of pathology spread. These lymph nodes act as filters, trapping and destroying pathogens filtered out of the lymph.
In conditions such as lymphogranuloma venereum, which is caused by certain serovars of C. trachomatis, the inguinal lymph nodes can become enlarged, forming buboes which may burst and release pus. The lymphatic system is essential in the immune response against pathogens. Additionally, lymphoma represents a type of cancer that can originate within the lymph nodes themselves.