The glomus forms from the splanchnic intermediate mesoderm and is the vascularized filtration unit, filtering the blood before it enters the tubules. The glomus is external to the nephron and extends over more than one body segment. [ http://www.ncbi.nlm.nih.gov/pubmed/9268568 http://www.ncbi.nlm.nih.gov/pubmed/15647339 http://www.ncbi.nlm.nih.gov/pubmed/10572058 XAO:0000318 http://dx.doi.org/10.1371/journal.pone.0099864 http://amigo.geneontology.org/amigo/term/GO:0072013 GOC:mtg_kidney_jan10 ]