Emtree is a controlled vocabulary that facilitates consistent description of biomedical information by including nearly 300,000 synonyms for search terms. It is comprehensive, covering drugs & chemicals, diseases, procedures, anatomical concepts, and much more.
Controlled vocabularies ensure that all results related to a given topic are returned, even if the term has several synonyms. Searching for the brand name of a drug like "Advil" or "Motrin" only returns limited results, but searching for the suggested Emtree term and generic drug name, Ibuprofen, returns nearly 50,000.
You can easily broaden or refine your search by moving up or down Emtree's hierarchical structure.
Using a higher term in the hierarchy, like animal structures, will broaden your results. Using a lower term, like antennule, will narrow them.
MeSH terms are included in Emtree, allowing a smooth transition from other databases like PubMed or Medline. An in-depth comparison of Emtree and MeSH is available here.
Emtree terms are updated three times yearly.