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urorectal septum

^ http://purl.obolibrary.org/obo/UBERON_0005760


The ridge of mesoderm covered with endoderm that in the early developing embryo partitions the endodermal cloaca into the primary urogenital sinus (ventrally) and the anorectal canal of the hindgut (dorsally); the urorectal septum eventually fuses with the cloacal membrane, dividing it into a dorsal anal membrane and a larger ventral urogenital membrane - this area of fusion is represented in the adult by the perineal body[MP]. [ MP:anna http://en.wikipedia.org/wiki/Urorectal_septum ]

Synonyms: urorectal membrane, urorectal fold, septum urorectale

Term info

database cross reference
Subsets

pheno_slim

UBPROP 0000001

A ridge of mesoderm covered with endoderm that in the early developing embryo divides the endodermal cloaca into the urogenital sinus and the rectum. [TFD][VHOG]

UBPROP 0000003

In mammals the lowly monotremes still have a cloaca. Higher types have done away with this structure and have a separate anal outlet for the rectum. The monotreme cloaca shows the initiation of this subdivision. The cloaca has such includes only the distal part, roughly comparable to the proctodeum. The more proximal part is divided into (1) a large dorsal passage into which the intestine opens, the coprodeum, and (2) a ventral portion, the urodeum with which the bladder connects. (...) the development of the placental mammals recapitulates in many respects the phylogenetic story. In the sexually indifferent stage of placental mammal there is a cloaca. While the indifferent stage still persists, a septum develops, and extends out to the closing membrane. This divides the cloaca into two chambers: a coprodeum continuous with the gut above, and a urodeum or urogenital sinus below.[well established][VHOG]

depicted by

http://upload.wikimedia.org/wikipedia/commons/f/fb/Gray992.png

editor note

todo - use to define cloacal septation in GO

has related synonym

cloacal septum

id

UBERON:0005760