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    Related Topics

    From Digestive System

    Hepatic Flexure
    Bend between ascending and transverse colon.
    Falciform Ligament
    Connects liver to anterior abdominal wall.
    Tail of Pancreas
    Tapered end of pancreas near spleen.
    Rectum
    Straight section of the colon leading to anus.
    Head of Pancreas
    Widest part of pancreas nestled in duodenum.
    Teniae Coli
    Longitudinal muscle bands of colon.
    Sublingual Glands
    Salivary glands beneath the tongue.
    Neck of Pancreas
    Short section between head and body.
    Cheeks
    Lateral walls of the oral cavity composed of muscle and fat.
    Main Pancreatic Duct
    Primary duct draining pancreatic juices.
    Duodenal Bulb
    Initial section of duodenum closest to the stomach.
    External Anal Sphincter
    Voluntary muscle around anus.
    Lesser Omentum
    Connects stomach and liver.
    Common Bile Duct
    Conveys bile from liver and gallbladder to duodenum.
    Body of Pancreas
    Central elongated portion of pancreas.
    Caudate Lobe
    Lobe of liver near inferior vena cava.
    Oropharynx
    Middle region of the pharynx behind the oral cavity.
    Stomach
    Muscular sac that begins digestion of protein.
    Lower Esophageal Sphincter
    Muscle at the junction of esophagus and stomach.
    Ascending Colon
    Vertical segment of the colon on the right side.
    Transverse Colon
    Horizontal part of the colon.
    Gallbladder
    Stores and concentrates bile.
    Hard Palate
    Bony anterior portion of the roof of the mouth.
    Mesentery
    Fold of peritoneum anchoring intestines.
    Ileum
    Final and longest portion of the small intestine.

    Mesocolon

    Reviewed by our medical team

    Peritoneal fold attaching colon to posterior wall.

    Overview

    The mesocolon is a fold of peritoneum that attaches parts of the colon to the posterior abdominal wall. It serves as a conduit for blood vessels, lymphatics, and nerves, and plays an important role in anchoring and supplying the large intestine. Different segments of the colon have their own mesocolons, and together they contribute significantly to the mobility, vascularization, and surgical organization of the colon.

    Location

    The mesocolon is located in the abdominal cavity and connects the colon to the posterior parietal peritoneum. It is subdivided into region-specific parts:

    • Transverse mesocolon: Suspends the transverse colon and attaches it to the posterior abdominal wall along the pancreas

    • Sigmoid mesocolon: Connects the sigmoid colon to the pelvic wall

    • Mesoappendix: A smaller mesentery for the vermiform appendix, extending from the terminal ileum

    • Ascending and descending mesocolons: These are usually fused to the posterior wall (retroperitoneal) but may remain mobile in some individuals

    Structure

    The mesocolon is made up of:

    • Two layers of peritoneum: Forming a double fold containing connective tissue and fat

    • Blood vessels: Including branches of the superior and inferior mesenteric arteries and veins

    • Lymphatics and lymph nodes: Supporting immune surveillance and drainage

    • Nerves: From the autonomic nervous system (both sympathetic and parasympathetic)

    Each mesocolon also provides the structural pathway for segment-specific vasculature and lymphatic drainage.

    Function

    The mesocolon serves several key anatomical and physiological functions:

    • Anchors the colon: Maintains the position of the colon in the abdominal cavity while allowing necessary mobility for peristalsis

    • Conduit for vessels and nerves: Facilitates the delivery of oxygen, nutrients, lymphatic drainage, and neural input to the colon

    • Supports mesenteric fat: Acts as a cushion and energy store while supporting embedded vessels and lymph nodes

    Physiological Role(s)

    The mesocolon supports digestive physiology by:

    • Facilitating motility: Allows segmental movement and peristalsis of the colon for fecal transport and water absorption

    • Enabling immune defense: Hosts lymphoid tissue and nodes involved in monitoring antigens from the colon

    • Maintaining vascular integrity: Supports arterial and venous return from the colon to systemic and portal circulations

    Clinical Significance

    The mesocolon is important in several clinical contexts:

    • Colorectal surgery: Mesocolon dissection is essential during colectomy and cancer resections; complete mesocolic excision (CME) aims to remove the colon and its mesentery as a single unit

    • Ischemic colitis: Vascular compromise in mesocolic vessels (e.g., inferior mesenteric artery) can cause ischemia, particularly in watershed areas like the splenic flexure

    • Internal hernias: Congenital or acquired defects in the mesocolon can allow loops of bowel to become trapped, leading to obstruction

    • Diverticulitis: Inflammation of the colon may involve adjacent mesocolic fat and lymph nodes, visible on imaging as “fat stranding”

    • Mesocolic lymphadenopathy: May occur in infections, inflammatory bowel disease, or metastatic spread from colorectal or other gastrointestinal cancers

    • Radiological evaluation: CT and MRI are often used to assess mesocolic pathology, especially in oncologic staging and surgical planning

    Understanding the mesocolon’s segmental anatomy is crucial for surgical resection, vascular management, and interpretation of imaging findings in colonic diseases.

    Did you know? The stomach acid is strong enough to dissolve metal, but the stomach lining protects itself from being digested!