part of part of develops from develops from extraembryonic structure embryonic structure chorion membrane chorionic plate chorionic villus http://upload.wikimedia.org/wikipedia/commons/1/1e/Gray29.png chorionic villous SCTID:360403003 chorionic villus embryonic part of placenta NCIT:C34125 UMLS:C0008508 villous chorion embryonic placenta placental villous The bulk of the villi consist of connective tissues in which blood vessels are found. Most of the cells in the connective tissue core of the villi are fibroblasts. Macrophages known as Hofbauer cells are also present. fetal placenta EHDAA2:0004717 chorionic villi villous of placenta fetal part of placenta Wikipedia:Chorionic_villi MESH:D002824 The mouse and human placentas have labyrinthine and villous types of interdigitation between maternal and fetal tissues, respectively BTO:0001161 placental villus UBERON:0007106 One of the minute vascular projections of the fetal chorion that combines with maternal uterine tissue to form the placenta. placental villi