lecture 9-part 2 - colon Flashcards
Colon: Divisions
Ascending
Transverse
Descending
Sigmoid
Ascending colon
– Right side of abdomen from caecum to right
lobe of liver
– Right colic flexure (hepatic flexure)
* Deep to 9th and 10th ribs
* Overlapped by inferior part of liver
transverse colon
– From right colic flexure to left colic flexure
- Is mobile, means it has a mesentery = transverse mesocolon
* Anterior to inferior part of kidney
* Attached to diaphragm by phrenicocolic
Descending colon
– Between left colic flexure and left iliac fossa – Anterior to lateral border of left kidney
Sigmoid colon
– From iliac fossa to S3
– Rectosigmoid junction
Colon is attached to the surface of the large intestine via
Omental appendices
= small pouches of peritoneum, filled with fat.
Taeniae coli
(3 strips of muscle fibres)
* – Thickened bands of smooth muscle
* – Length of large intestine, merge at rectosigmoid junction
Haustra
– Sacculations of the wall between the taeniae
Large intestine much wider than small intestine
Colon: Arterial supply
- From both SMA and IMA
Ascending colon
* – Ileocolic and right colic aa
* – Anastomose with right middle colic a
Transverse colon
* – Middle colic a
* – Anastomoses with right and left colic aa
Descending colon
– Left colic a
Sigmoid colon
– Sigmoid branches (from IMA)
Colon: Venous drainage
- Ascending colon – Ileocolic and right colic vv
- Transverse colon – Superior mesenteric v
- Descending colon & Sigmoidcolon – IMV
Colon: Lymphatics
Ascending colon
* – Epiploic and paracolic nodes
* – Ileocolic and right colic nodes
* – Superior mesenteric nodes
Transverse colon
* – Middle colic nodes
* – Superior mesenteric nodes
Descending colon & Sigmoid colon
* – Epiploic and paracolic nodes
* – Left colic nodes
* – Inferior mesenteric nodes
