Cloaca Development: Difference between revisions
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==Introduction== | ==Introduction== | ||
[[File:Stage12 sem9 cloacal membrane.jpg|alt=Carnegie stage 12 cloacal membrane|thumb|Human Embryo stage {{CS12}} cloacal membrane (SEM}]] | [[File:Stage12 sem9 cloacal membrane.jpg|alt=Carnegie stage 12 cloacal membrane|thumb|Human Embryo stage {{CS12}} cloacal membrane (SEM}]] | ||
The initial {{cloaca}} is the common early endoderm lined space of the {{hindgut}} that will later become partitioned by a septum into a dorsal gastrointestinal component (rectum) and ventral renal/genital component (urogenital sinus). Note that the cloaca in mammals is an early embryonic transient structure and only persists in birds and reptiles. Located at the superior end of the cloaca is the {{allantois}}, that extends into the connecting stalk and later the placental cord. Located at the inferior end of the cloaca is the cloacal membrane, that also forms part of the embryo surface. | The initial {{cloaca}} is the common early endoderm lined space of the {{hindgut}} that will later become partitioned by a septum into a dorsal gastrointestinal component (rectum) and ventral renal/genital component (urogenital sinus). Note that the cloaca in mammals is an early embryonic transient structure and only persists in birds and reptiles. Located at the superior end of the cloaca is the {{allantois}}, that extends into the connecting stalk and later the placental cord. Located at the inferior end of the cloaca is the {{cloacal membrane}}, that also forms part of the embryo surface. | ||
The gastrointestinal tract ends at this cloacal membrane, equivalent to the beginning of the tract at the buccopharyngeal membrane at the upper end. The cloacal membrane is formed during gastrulation by {{ectoderm}} and {{endoderm}} without a middle (intervening) layer of {{mesoderm}}, that later degenerates after cloacal septation. | The gastrointestinal tract ends at this cloacal membrane, equivalent to the beginning of the tract at the buccopharyngeal membrane at the upper end. The cloacal membrane is formed during gastrulation by {{ectoderm}} and {{endoderm}} without a middle (intervening) layer of {{mesoderm}}, that later degenerates by {{apoptosis}} after cloacal septation. | ||
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:'''Links:''' {{cloaca}} | {{Intestine}} | {{bladder}} | {{genital}} | :'''Links:''' {{cloaca}} | {{Intestine}} | {{bladder}} | {{genital}} | {{apoptosis}} | ||
:: [[Historic Embryology Papers|Historic papers]]: [[Paper - The development of the cloaca in human embryos|1911 human cloaca]] | [[Book_-_Manual_of_Human_Embryology_19-1#Cloaca.2C_Bladder.2C_Urethra.2C_and_Urogenital_Sinus|1912 Cloaca, Bladder, Urethra, and Urogenital Sinus]] | [[Paper - The Early Development of Man, with Special Reference to the Development of the Mesoderm and Cloacal Membrane|1933 Cloacal Membrane]] | [[Paper - Congenital hernia into the umbilical cord - two cases, one associated with persistent cloaca|1938 persistent cloaca]] | :: [[Historic Embryology Papers|Historic papers]]: [[Paper - The development of the cloaca in human embryos|1911 human cloaca]] | [[Book_-_Manual_of_Human_Embryology_19-1#Cloaca.2C_Bladder.2C_Urethra.2C_and_Urogenital_Sinus|1912 Cloaca, Bladder, Urethra, and Urogenital Sinus]] | [[Paper - The Early Development of Man, with Special Reference to the Development of the Mesoderm and Cloacal Membrane|1933 Cloacal Membrane]] | [[Paper - Congenital hernia into the umbilical cord - two cases, one associated with persistent cloaca|1938 persistent cloaca]] | ||
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Revision as of 13:41, 14 November 2018
Embryology - 19 Apr 2024 Expand to Translate |
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Introduction
The initial cloaca is the common early endoderm lined space of the hindgut that will later become partitioned by a septum into a dorsal gastrointestinal component (rectum) and ventral renal/genital component (urogenital sinus). Note that the cloaca in mammals is an early embryonic transient structure and only persists in birds and reptiles. Located at the superior end of the cloaca is the allantois, that extends into the connecting stalk and later the placental cord. Located at the inferior end of the cloaca is the cloacal membrane, that also forms part of the embryo surface.
The gastrointestinal tract ends at this cloacal membrane, equivalent to the beginning of the tract at the buccopharyngeal membrane at the upper end. The cloacal membrane is formed during gastrulation by ectoderm and endoderm without a middle (intervening) layer of mesoderm, that later degenerates by apoptosis after cloacal septation.
The hindgut component will contribute to the gastrointestinal tract intestine of the distal transverse colon, descending colon, sigmoid colon, rectum.
The urogenital sinus component will contribute the renal urinary bladder and participate in genital development.
Some Recent Findings
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More recent papers |
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This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.
More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Cloaca <pubmed limit=5>Cloaca</pubmed>
<pubmed limit=5>Cloacal Membrane</pubmed> |
Older papers |
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These papers originally appeared in the Some Recent Findings table, but as that list grew in length have now been shuffled down to this collapsible table.
See also the Discussion Page for other references listed by year and References on this current page. |
Movies
Early Endoderm | Week 3 Folding |
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<html5media height="400" width="350">File:Amnion 001.mp4</html5media> | <html5media height="500" width="350">File:Week3_folding.mp4</html5media> |
- Links: Early Endoderm Movie | Week 3 Folding Movie
Embryonic Development
Stage 10
Caudal end of embryo showing primitive streak region, cloacal membrane, and connecting stalk. |
- Links: Carnegie stage 10 | Stage 10 Movie
Stage 11
Historic image<ref name=Low1908>Low A. Description of a human embryo of 13-14 mesodermic somites. (1908) J Anat Physiol. 42(3): 237-51. PMID 17232769 | PMC1289161 of an embryo model (sagittal section, viewed from the left) showing hindgut and cloaca. |
- Links: Carnegie stage 11
Stage 12
- ===Stage 13===
- ===Stage 22===
- ==Abnormalities==
- ===Persistent Cloaca Perineum===
- ===Cloacal Exstrophy===
- ==References==
- ===Books===
- ===Reviews===
- ===Articles===
- ===Historic===
- ===Search Pubmed===
- ==Additional Images==
- ===Historic===
Fig. 600. Embryo Pfannenstiel III 2.6 mm GL 13-14 somites, allantoic stalk is given off at a right angle from the cloaca, immediately above cloacal membrane. Ventral wall of the cloaca is formed only by the cloacal membrane.
Fig. 605. Human embryo 5.3 mm GL (Embryo 1420) Primary excretory duct and opening with reference to cloaca and cloacal membrane, anlage of ureteric bud.
Florian J. The early development of man, with special reference to the development of the mesoderm and cloacal membrane. (1933) J. Anat., 67(2): 263-76. PMID 17104422
Terms
- cloacal duct of Reichel - Reichel P. The development of the bladder and urinary tubes (Die Entwicklung der Harnblase und der Harnrohre), (1893) Verb. phys. med. Gesellsch. Wiirzburg.
- cloacal tubercle - (genital tubercle)
Gastrointestinal Tract Terms | ||
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Glossary Links
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Cite this page: Hill, M.A. (2024, April 19) Embryology Cloaca Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Cloaca_Development
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G