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/15647339 http://www.ncbi.nlm.nih.gov/pubmed/9268568 http://dx.doi.org/10.1371/journal.pone.0099864 GOC:mtg_kidney_jan10 http://www.ncbi.nlm.nih.gov/pubmed/10572058 http://amigo.geneontology.org/amigo/term/GO:0072013 XAO:0000318 ]