Urorectal septum
Encyclopedia
The entodermal cloaca
is divided into a dorsal and a ventral part by means of a partition, the urorectal septum, which grows downward from the ridge separating the allantoic from the cloacal opening of the intestine
and ultimately fuses with the cloacal membrane and divides it into an anal and a urogenital part. The dorsal part of the cloaca forms the rectum
, and the anterior part of the urogenital sinus
and bladder
.
s.
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...
is divided into a dorsal and a ventral part by means of a partition, the urorectal septum, which grows downward from the ridge separating the allantoic from the cloacal opening of the intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
and ultimately fuses with the cloacal membrane and divides it into an anal and a urogenital part. The dorsal part of the cloaca forms the rectum
Rectum
The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
, and the anterior part of the urogenital sinus
Urogenital sinus
The definitive urogenital sinus is a part of the human body only present in the development of the urinary and reproductive organs...
and bladder
Urinary bladder
The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
.
Clinical significance
Malformation of the urorectal septum can lead to several different types of fistulaFistula
In medicine, a fistula is an abnormal connection or passageway between two epithelium-lined organs or vessels that normally do not connect. It is generally a disease condition, but a fistula may be surgically created for therapeutic reasons.-Locations:Fistulas can develop in various parts of the...
s.
External links
- http://cancerweb.ncl.ac.uk/cgi-bin/omd?urorectal+septum
- http://www.embryology.ch/anglais/turinary/urinbasse01.html
- http://isc.temple.edu/marino/embryology/parch98/parch_text.htm
- http://www.med.mun.ca/anatomyts/renal/akid5.htm
- http://www.med.umich.edu/lrc/coursepages/M1/embryology/embryo/10digestivesystem.htm