Lymphovascular Supply

Embryologically the gastrointestinal tract is divided into three segments (fore, mid and hindgut) with each region being supplied by its own artery:

• Coeliac artery supplies the foregut (distal oesophagus to the mid-portion of the second part of the duodenum).

• Superior mesenteric artery supplies the midgut (mid-portion of the second part of the duodenum to the junction of the proximal two thirds and distal third of the transverse colon).

• Inferior mesenteric artery supplies the hindgut (distal third of the transverse colon to the junction of the superior and inferior half of the anal canal).

The rectum is also supplied by branches of the internal iliac artery. The anastomosis of the colic arteries around the concavity of the colon forms the marginal artery. The venous drainage of the colon is to the portal venous system and the rectum to the inferior mesenteric and internal iliac veins.

Figure 5.4. Colorectum: regional lymph nodes. The regional lymph nodes are the pericolic and perirectal and those located along the ileocolic, right colic, middle colic, left colic, inferior mesenteric, superior rectal (haemorrhoidal) and internal iliac arteries. Reproduced with permission from Hermanek P, Hutter RVP, Sobin, LH, Wagner, G, Wittekind, Ch. (Eds). TNM Atlas: Illustrated guide to the TNM/pTNM classification of malignant tumours, 4th edition. Springer-Verlag: Berlin and Heidelberg, 1997.

Figure 5.4. Colorectum: regional lymph nodes. The regional lymph nodes are the pericolic and perirectal and those located along the ileocolic, right colic, middle colic, left colic, inferior mesenteric, superior rectal (haemorrhoidal) and internal iliac arteries. Reproduced with permission from Hermanek P, Hutter RVP, Sobin, LH, Wagner, G, Wittekind, Ch. (Eds). TNM Atlas: Illustrated guide to the TNM/pTNM classification of malignant tumours, 4th edition. Springer-Verlag: Berlin and Heidelberg, 1997.

The lymphatics accompany the colic vessels draining to the superior and inferior mesenteric nodes. Those from the rectum drain into nodes (pararectal nodes) situated in the perirectal connective tissue (mesorectum) and thence to the superior mesenteric and internal iliac nodes (Figure 5.4).

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