phylum. 1  Biology. the primary subdivision of a taxonomic kingdom, grouping together all classes of organisms that have the same body plan. 2  Linguistics. a category consisting of language stocks that, because of cognates in vocabulary, are considered likely to be related by common origin. Compare stock (def 13).
There are between 500 and 600 lymph nodes in the average adult human body.
When the immune system is activated they begin producing large numbers of lymphocytes which causes them to swell. There are about 500-700 lymph nodes spread throughout the body. Click on the diagrams below for highly detailed pictures of where the lymph nodes are located.