Large Intestine

• Reabsorbs water.
• Omental appendices are small fatty projections that help with immune responses and cushion the colon.
• Teniae Coli are thickened bands of muscle. 3 types; mesocolic, omental, and free
• Haustra are saccules (little sacs) in the colon that give it its segmented appearance
• Caecum starts at ileocecal Junction. 7.5cm pouch. No mesentery.
• Appendix is an intestinal diverticulum 6-10cm in length. Contains masses of lymphoid tissue. Small meso-appendix.
• Rectum is retroperitoneal. S3 vertebra level. S shaped. Transverse rectal folds.
• Arterial supply: sup. Mesenteric a. = ileocolic, right colic, middle colic. Inf. MesentEric a. = left colic, superior sigmoid, sigmoid arteries
• Arterial supply: sup. Mesenteric a. = ileocolic, right colic, middle colic. Inf. MesentEric a. = left colic, superior sigmoid, sigmoid arteries
• Venous return: sup. Mesenteric runs to hepatic portal vein. Inf. Mesenteric runs to splenic. Joins superior mesenteric to become hepatic portal vein.
• Caecum and Appendix drain to appendicular and ileocolic lymph nodes
• Ascending colon drains to ileocolic and right colic lymph nodes
• Descending and sigmoid colon drain to left colic (intermediate) lymph nodes
• The pancreas is an accessory digestive gland. Retroperitoneal. L1-2 level. Exorcise function - pancreatic juice from acinar cells. Endocrine function - glucagon and insulin from islet cells