Colon - supply
arterial supply
| Part of large intestine | Main vessel supplying | Origin of vessel |
|---|---|---|
| Appendix & caecum | ileocolic | Superior mesenteric |
| Ascending colon | right colic | Superior mesenteric |
| Transverse | middle colic (left colic supplies distal 1/3) |
Superior mesenteric |
| Descending | left colic | Inferior mesenteric |
| Sigmoid | sigmoid branches | Inferior meseteric |
| Rectum | superior rectal branches | inferior mesenteric |
splenic flexure = watershed
venous drainage
- Ascending colon – ileocolic and right colic veins, which empty into the superior mesenteric vein.
- Transverse colon – middle colic vein, which empties into the superior mesenteric vein.
- Descending colon – left colic vein, which drains into the inferior mesenteric vein.
- Sigmoid colon – drained by the sigmoid veins into the inferior mesenteric vein.
lymphatic drainage
superior mesenteric nodes
innervation
... cutoff = distal ⅓ of transverse colon
proximal to that = T10-12
distal to that = L1-2
- Parasympathetic innervation via the pelvic splanchnic nerves
- Sympathetic innervation via the lumbar splanchnic nerves.
referred pain
- ascending + transverse (midgut): via T10-11/lesser splanchnic
- descending + sigmoid (hindgut): via L1-2/lumbar splanchnic