Sigmoid colon
Hidden edits. Some edits not affecting the appearance of this article have been suppressed.
Updates to Article Attributes
Body
was changed:
The sigmoid colon is the continuation of the descending colon.
Gross morphology and relationsanatomy
After the distal descending colon has curved medially it enters the pelvis, where it gains a mesentery and is then called the sigmoid colon. It measures approximately 15cm15 cm in length.
It has a "S" (Greek letter sigma) shape and has a variable length and course - its apex may be as high as the umbilicus. It lies on its own mesentery - the inverted V-shaped sigmoid mesocolon.
The sigmoid colon continues as the rectum when it loses its mesentery, at approximately S3.
Relations
- anteriorly
- superiorly
- loops: loops of small intestine - posteriorly: left internal iliac artery and vein, left ureter, piriformis muscle, sacrum, sacral plexus
- laterally
- male
- pelvic: pelvic side wall, vas deferens - female
- pelvic: pelvic side wall, ovary
- male
Blood supply
- arterial
- two: two-to-four sigmoid arteries (branch of inferior mesenteric artery) - venous
- similarly: similarly named veins drain into the inferior mesenteric vein
Nerve supply
- sympathetic
- inferior: inferior mesenteric plexus - parasympathetic
- via: via pelvic splanchnic nerves (from S2-S4)
LymphaticsLymphatic drainage
Lymphatics travel with vessels to the inferior mesenteric group.
Related pathology
-<p>The <strong>sigmoid colon</strong> is the continuation of the <a href="/articles/descending-colon" title="Descending colon">descending colon</a>.</p><h4>Gross morphology and relations</h4><p>After the distal descending colon has curved medially it enters the <a href="/articles/pelvis-1" title="Pelvis">pelvis</a>, where it gains a mesentery and is then called the sigmoid colon. It measures approximately 15cm in length. </p><p>It has a "S" (Greek letter <em>sigma</em>) shape and has a variable length and course - its apex may be as high as the <a href="/articles/umbilicus" title="umbilicus">umbilicus</a>. It lies on its own <a href="/articles/mesentery" title="Mesentery" style="line-height: 1.5;">mesentery</a> - the inverted V-shaped <a href="/articles/sigmoid-mesocolon" title="Sigmoid mesocolon">sigmoid mes</a><a href="/articles/sigmoid-mesocolon" title="Sigmoid mesocolon">ocolon</a>.</p><p>The sigmoid colon continues as the <a href="/articles/rectum" title="rectum">rectum</a> when it loses its mesentery, at approximately S3. </p><h5>Relations</h5><ul>- +<p>The <strong>sigmoid colon</strong> is the continuation of the <a href="/articles/descending-colon">descending colon</a>.</p><h4>Gross anatomy</h4><p>After the distal descending colon has curved medially it enters the <a href="/articles/pelvis-1">pelvis</a>, where it gains a mesentery and is then called the sigmoid colon. It measures approximately 15 cm in length. </p><p>It has a "S" (Greek letter <em>sigma</em>) shape and has a variable length and course - its apex may be as high as the <a href="/articles/umbilicus">umbilicus</a>. It lies on its own <a href="/articles/mesentery">mesentery</a> - the inverted V-shaped <a href="/articles/sigmoid-mesocolon">sigmoid mes</a><a href="/articles/sigmoid-mesocolon">ocolon</a>.</p><p>The sigmoid colon continues as the <a href="/articles/rectum">rectum</a> when it loses its mesentery, at approximately S3. </p><h5>Relations</h5><ul>
-<li>male - <a href="/articles/bladder" title="bladder">bladder</a>-</li>-<li>female - bladder and <a href="/articles/uterus" title="Uterus">uterus</a>-</li>- +<li>male: <a href="/articles/bladder">bladder</a>
- +</li>
- +<li>female: bladder and <a href="/articles/uterus">uterus</a>
- +</li>
-</li>-<li>superiorly - loops of <a href="/articles/small_bowel(textbook)" title="small intestine">small intestine</a>-</li>-<li>posteriorly - left <a href="/articles/internal-iliac-artery" title="Internal iliac artery">internal iliac artery</a> and vein, left <a href="/articles/ureter" title="ureter">ureter</a>, <a href="/articles/piriformis" title="Piriformis muscle">piriformis</a> muscle, <a href="/articles/sacrum" title="sacrum">sacrum</a>, <a href="/articles/sacral-plexus" title="sacral plexus">sacral plexus</a>-</li>- +</li>
- +<li>superiorly: loops of <a href="/articles/small-bowel">small intestine</a>
- +</li>
- +<li>posteriorly: left <a href="/articles/internal-iliac-artery">internal iliac artery</a> and vein, left <a href="/articles/ureter">ureter</a>, <a href="/articles/piriformis">piriformis</a> muscle, <a href="/articles/sacrum">sacrum</a>, <a href="/articles/sacral-plexus">sacral plexus</a>
- +</li>
-<li>male - pelvic side wall, <a href="/articles/vas-deferens" title="vas deferens">vas deferens</a>-</li>-<li>female - pelvic side wall, <a href="/articles/ovaries" title="Ovary">ovary</a>-</li>- +<li>male: pelvic side wall, <a href="/articles/vas-deferens">vas deferens</a>
- +</li>
- +<li>female: pelvic side wall, <a href="/articles/ovaries">ovary</a>
- +</li>
-</li>- +</li>
-<li>arterial - two-to-four <a href="/articles/sigmoid-arteries" title="Sigmoid arteries">sigmoid arteries</a> (branch of<a href="/articles/inferior-mesentric-artery" title="Inferior mesenteric artery (IMA) "> inferior mesenteric artery</a>) </li>-<li>venous - similarly named veins drain into the <a href="/articles/inferior-mesenteric-vein" title="inferior mesenteric vein">inferior mesenteric vein</a>-</li>- +<li>arterial: two-to-four <a href="/articles/sigmoid-arteries">sigmoid arteries</a> (branch of<a href="/articles/inferior-mesenteric-artery"> inferior mesenteric artery</a>) </li>
- +<li>venous: similarly named veins drain into the <a href="/articles/inferior-mesenteric-vein">inferior mesenteric vein</a>
- +</li>
-<li>sympathetic - inferior mesenteric plexus </li>-<li>parasympathetic - via pelvic splanchnic nerves (from S2-S4)</li>-</ul><h4>Lymphatics</h4><p>Lymphatics travel with vessels to the inferior mesenteric group.</p><h4>Related pathology</h4><ul><li><a href="/articles/sigmoid-volvulus" title="Sigmoid volvulus">sigmoid volvulus</a></li></ul>- +<li>sympathetic: inferior mesenteric plexus </li>
- +<li>parasympathetic: via pelvic splanchnic nerves (from S2-S4)</li>
- +</ul><h4>Lymphatic drainage</h4><p>Lymphatics travel with vessels to the inferior mesenteric group.</p><h4>Related pathology</h4><ul><li><a href="/articles/sigmoid-volvulus">sigmoid volvulus</a></li></ul>
Images Changes:
Image 1 Diagram ( create )
Unable to process the form. Check for errors and try again.