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    Related Topics

    From Digestive System

    Accessory Pancreatic Duct
    Secondary duct emptying into duodenum.
    Body of Pancreas
    Central elongated portion of pancreas.
    Teeth
    Structures in the jaws for mechanical breakdown of food.
    Pancreas
    Gland with both endocrine and exocrine functions.
    Falciform Ligament
    Connects liver to anterior abdominal wall.
    Tail of Pancreas
    Tapered end of pancreas near spleen.
    Parotid Glands
    Largest salivary glands located near the ear.
    Gallbladder
    Stores and concentrates bile.
    Common Bile Duct
    Conveys bile from liver and gallbladder to duodenum.
    Laryngopharynx
    Lower part of pharynx leading to esophagus.
    Submandibular Glands
    Salivary glands beneath the mandible.
    Ascending Colon
    Vertical segment of the colon on the right side.
    Teniae Coli
    Longitudinal muscle bands of colon.
    Palatine Tonsils
    Lymphatic tissues on either side of the oropharynx.
    Cardia
    Upper opening of the stomach.
    Gingiva
    Gums; soft tissue covering the bones of the jaw.
    Abdomen
    The abdomen is the body region between the chest and pelvis housing vital digestive, metabolic, and excretory organs, protected by muscular and peritoneal layers.
    Ileocecal Valve
    Controls flow from ileum to cecum.
    Sigmoid Colon
    S-shaped final segment of the colon.
    Main Pancreatic Duct
    Primary duct draining pancreatic juices.
    Upper Esophageal Sphincter
    Muscle ring that controls entry into the esophagus.
    Ileum
    Final and longest portion of the small intestine.
    Soft Palate
    Muscular posterior part of the roof of the mouth.
    Uvula
    Dangling soft tissue at the back of the soft palate.
    Hard Palate
    Bony anterior portion of the roof of the mouth.

    Mesentery

    Reviewed by our medical team

    Fold of peritoneum anchoring intestines.

    Overview

    The mesentery is a continuous fold of double-layered peritoneum that attaches portions of the intestine to the posterior abdominal wall. It acts as a supportive and suspensory structure while serving as a conduit for blood vessels, lymphatics, and nerves. Once considered a fragmented structure, recent anatomical understanding classifies the mesentery as a single, continuous organ that plays vital roles in digestion, immunity, and structural integrity of the gut.

    Location

    The mesentery is located in the abdominal cavity and is classified based on the portion of the gastrointestinal tract it supports:

    • The mesentery proper: Connects the jejunum and ileum to the posterior abdominal wall

    • Mesocolon: Includes the transverse mesocolon, sigmoid mesocolon, and mesoappendix

    • Mesorectum: Attaches the rectum to the sacrum and posterior pelvic wall

    • Other mesenteries: Include the mesogastrium (stomach) and mesoduodenum (first parts of duodenum)

    All mesenteric structures arise from the dorsal mesentery during embryological development, except the ventral mesentery of the foregut.

    Structure

    The mesentery consists of:

    • Two layers of peritoneum: Enclosing connective tissue and a loose fatty matrix

    • Blood vessels: Including branches of the superior mesenteric artery and vein for the small intestine

    • Lymphatic vessels: Important for fat absorption and immune cell trafficking

    • Nerves: Derived from the autonomic plexuses to innervate the intestines

    • Lymph nodes: Embedded within the mesentery for gut-associated immune response

    The mesentery has a root approximately 15 cm long, obliquely oriented from the left upper quadrant (L2) to the right lower quadrant (sacroiliac region).

    Function

    The mesentery serves several essential functions:

    • Suspends the intestine: Anchors the intestines while allowing mobility for peristalsis and digestion

    • Supports neurovascular supply: Conveys arteries, veins, lymphatics, and nerves to the intestines

    • Maintains gut alignment: Prevents intestinal twisting or volvulus

    • Pathway for immune cells: Houses lymph nodes and immune cells involved in gut immunity

    Physiological Role(s)

    The mesentery contributes to overall digestive physiology through:

    • Absorption of nutrients: Transports absorbed nutrients, including fats via lacteals, from the intestines to the bloodstream

    • Fat storage: The mesentery contains adipose tissue that serves as an energy reserve and insulator

    • Immune surveillance: Lymph nodes filter antigens and coordinate immune responses to pathogens in the gut

    • Inflammatory signaling: Plays a role in local inflammatory responses, particularly in diseases like Crohn's

    Clinical Significance

    The mesentery is involved in various pathological and surgical conditions:

    • Mesenteric ischemia: Occlusion of mesenteric arteries can lead to intestinal infarction, a surgical emergency

    • Mesenteric lymphadenitis: Enlargement of mesenteric lymph nodes, often due to viral or bacterial infection

    • Mesenteric tumors: Includes rare neoplasms like mesenteric fibromatosis or liposarcoma

    • Inflammatory bowel disease: In Crohn's disease, mesenteric fat wrapping ("creeping fat") is a hallmark feature

    • Internal hernias: May involve mesenteric defects allowing bowel loops to protrude and cause obstruction

    • Mesenteric traction syndrome: A perioperative complication characterized by hypotension due to mesenteric manipulation

    • Surgical access and resection: Surgeons rely on the mesentery for vascular control in resections, transplants, or anastomoses

    Recent reclassification of the mesentery as a continuous organ has implications for surgery, imaging, embryology, and disease understanding. CT and MRI imaging are frequently used to assess mesenteric pathology.

    Did you know? Your gut contains millions of neurons and is often referred to as the "second brain."