Sigmoid colon
246027
222947087
2008-07-01T21:31:56Z
79.31.113.74
{{Infobox Anatomy |
Name = {{PAGENAME}} |
Latin = colon sigmoideum |
GraySubject = 249 |
GrayPage = 1182 |hello
Image = Dickdarm-Schema.svg |
Caption = 1: [[Ascending colon]]<BR>2: [[Transverse colon]]<BR>3: [[Descending colon]]<BR>4: [[Sigmoid colon]]<BR>5: [[Rectum]]<BR>|
Image2 = Gray1223.png |
Caption2 = Front of abdomen, showing surface markings for liver, stomach, and great intestine. |
Precursor = [[hindgut]] |
System = |
Artery = [[sigmoid arteries]] |
Vein = |
Nerve = [[superior mesenteric ganglia]], [[sacral nerve]] <ref>{{GeorgiaPhysiology|6/6ch2/s6ch2_30}}</ref> |
Lymph = |
MeshName = |
MeshNumber = |
DorlandsPre = c_47 |
DorlandsSuf = 12249909 |
}}
The '''sigmoid colon''' ('''pelvic colon'''; '''sigmoid flexure''') forms a loop which averages about 40 cm. in length, and normally lies within the [[pelvis]], but on account of its freedom of movement it is liable to be displaced into the [[abdominal cavity]].
==Path==
It begins at the [[superior aperture]] of the [[lesser pelvis]], where it is continuous with the [[iliac colon]], and passes transversely across the front of the [[sacrum]] to the right side of the pelvis.
It then curves on itself and turns toward the left to reach the middle line at the level of the third piece of the [[sacrum]], where it bends downward and ends in the [[rectum]]. According to [[Isaac Asimov]]'s book ''The Human Body,'' the name ''sigmoid'' means "[[S]]-shaped."
==Coverings==
It is completely surrounded by [[peritoneum]] (and thus is NOT [[Retroperitoneal]]), which forms a [[mesentery]] ([[sigmoid mesocolon]]), which diminishes in length from the center toward the ends of the loop, where it disappears, so that the loop is fixed at its junctions with the [[iliac colon]] and rectum, but enjoys a considerable range of movement in its central portion.
==Innervation==
[[Pelvic splanchnic nerves]] are the primary source for [[parasympathetic]] innervation.
==Relations==
Behind the sigmoid colon are the [[external iliac vessels]], the left [[Piriformis]], and left [[sacral plexus]] of nerves.
In front, it is separated from the [[Urinary bladder|bladder]] in the [[male]], and the [[uterus]] in the [[female]], by some coils of the [[small intestine]].
==Additional images==
<gallery>
Image:illu_intestine.jpg|Intestines
Image:Gray538.png|Sigmoid colon and rectum, showing distribution of branches of inferior mesenteric artery and their anastomoses.
Image:Gray1076.png|Iliac colon, sigmoid or pelvic colon, and rectum seen from the front, after removal of pubic bones and bladder.
<br> hi
Image:WeiblichesBeckenMedian.gif|Sagittal section of the lower part of a female trunk, right segment.
</gallery>
==References==
<references/>
==External links==
* {{eMedicineDictionary|Sigmoid+colon}}
* {{SUNYAnatomyFigs|37|06|07}} - "The large intestine."
* {{NormanAnatomy|sup&infmesentericart}}
{{Gray's}}
{{digestive-stub}}
{{Digestive tract}}
[[de:Colon sigmoideum]]
[[dv:ސިގްމޮއިޑް ގޮހޮރު]]
[[fr:Sigmoïde (anatomie)]]
[[it:Sigma (anatomia)]]
[[la:Colon sigmoideum]]
[[pl:Esica]]
[[pt:Sigmóide]]
[[ru:Сигмовидная кишка]]
[[sv:Colon sigmoideum]]