Trunk vessels (aorta, vena cava, abdominal branches)
Inferior mesenteric vein
Vena mesenterica inferior
- Origin
- Begins as the superior rectal vein draining the rectal venous plexus
- Insertion
- Ascends retroperitoneally on the psoas major, usually draining into the splenic vein (or superior mesenteric vein)
- Function
- Drains the distal transverse colon, descending colon, sigmoid colon, and upper rectum into the portal system
- Innervation
- Inferior mesenteric plexus
- Movement & chain
- Venous flow toward the splenic vein
- Palpation
- Not palpated directly
- Clinical
- Portosystemic anastomosis site at the rectal plexus: portal hypertension produces rectal varices via dilation of the communications between the superior rectal vein (portal) and middle/inferior rectal veins (systemic).
- Segmental innervation
- L1-L2 and S2-S4 spinal levels
- In clinical practice
- Endoscopic assessment and management of bleeding rectal varices in portal hypertension
- Region in the model
- Trunk vessels (aorta, vena cava, abdominal branches)