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    Related Topics

    From Lymphatic System

    Appendix
    Lymphoid-rich structure of the large intestine.
    Subscapular Axillary Nodes
    Located along the posterior chest wall.
    Pretracheal Nodes
    Located anterior to the trachea.
    Sacral Lymph Nodes
    Drain the pelvic floor and rectum.
    NALT
    Nasal-associated lymphoid tissue.
    Lumbar Trunk
    Drains lower limbs and pelvic organs.
    Thymus
    Primary lymphoid organ for T-cell maturation.
    Lymph Nodes
    Small structures that filter lymph and store immune cells.
    GALT
    Gut-associated lymphoid tissue.
    Palatine Tonsils
    Located on each side of the oropharynx.
    Deep Cervical Lymph Nodes
    Located along internal jugular vein; receive lymph from head and neck.
    Submandibular Lymph Nodes
    Drain the face, mouth, and pharynx.
    Occipital Lymph Nodes
    Drain the back of the scalp.
    Apical Axillary Nodes
    Located at the apex of the axilla.
    Central Axillary Nodes
    Located centrally in the armpit.
    Tubal Tonsils
    Near openings of the auditory tubes.
    Tracheobronchial Nodes
    Drain lungs and bronchi.
    Intestinal Trunk
    Drains lymph from the intestines.
    Submental Lymph Nodes
    Drain the floor of the mouth and central lower lip.
    MALT
    Mucosa-associated lymphoid tissue.
    Red Bone Marrow
    Produces lymphocytes; site of B-cell maturation.
    Lateral Axillary Nodes
    Located along the humerus in the axilla.
    SALT
    Skin-associated lymphoid tissue.
    Retroaortic Nodes
    Located behind the aorta.
    Cisterna Chyli
    Dilated sac at the start of the thoracic duct.

    Mesenteric Lymph Nodes

    Reviewed by our medical team

    Drain the intestines and abdominal structures.

    1. Overview

    Mesenteric lymph nodes are a large group of lymph nodes embedded within the mesentery—the double fold of peritoneum that anchors the intestines to the posterior abdominal wall. These nodes play a central role in the immune surveillance of the gastrointestinal tract, particularly the small intestine and parts of the colon. They are responsible for filtering lymph, responding to gut-derived antigens, and coordinating both local and systemic immune responses. They are part of the gut-associated lymphoid tissue (GALT) system.

    2. Location

    Mesenteric lymph nodes are located in the mesentery that suspends the small intestine and parts of the large intestine (especially the jejunum, ileum, and proximal colon). They are found in close proximity to the superior mesenteric artery (SMA) and its branches. These nodes can be grouped into three main layers:

    • Juxtaintestinal nodes: Closest to the intestinal wall

    • Intermediate mesenteric nodes: Along the arterial arcades and straight vessels

    • Central mesenteric nodes: Located near the root of the mesentery, along the SMA trunk

    Lymph from these nodes ultimately drains into the superior mesenteric lymph nodes, then into the intestinal lymphatic trunk, and finally into the cisterna chyli, which leads to the thoracic duct.

    3. Structure

    Mesenteric lymph nodes are small, oval, encapsulated structures composed of lymphoid tissue. They share the classic lymph node architecture, including:

    • Capsule: Dense connective tissue covering the node

    • Cortex: Contains lymphoid follicles with germinal centers rich in B cells

    • Paracortex: Rich in T cells and dendritic cells for antigen presentation

    • Medulla: Contains macrophages and plasma cells within medullary cords and sinuses

    • Afferent lymphatics: Carry lymph from the intestinal mucosa (via lacteals and submucosal plexuses)

    • Efferent lymphatics: Drain toward larger mesenteric and preaortic nodes

    These nodes are closely integrated with intestinal blood vessels and immune cells of the intestinal lamina propria.

    4. Function

    Mesenteric lymph nodes serve as a filtration and immunologic checkpoint for the gastrointestinal tract. Their main functions include:

    • Antigen filtration: Capture and process antigens from intestinal pathogens, food, and commensal microbiota

    • Immune cell activation: Provide a site for antigen presentation to lymphocytes, triggering adaptive immune responses

    • Immunoglobulin production: Support B-cell class switching and IgA production

    • Lipid transport: Indirectly assist in the transport of chylomicrons and absorbed fats through associated lymphatic channels

    5. Physiological Role(s)

    These nodes are deeply involved in maintaining immune homeostasis in the gut and systemic circulation:

    • Barrier defense: Act as a second line of defense following epithelial immunity of the intestinal mucosa

    • Microbiota regulation: Help distinguish between pathogenic microbes and harmless commensals to prevent overactivation of immunity

    • Oral tolerance induction: Facilitate immune tolerance to dietary antigens and prevent food allergies or unnecessary inflammation

    • Gut–lymph interface: Mediate immune responses in concert with Peyer's patches and other GALT components

    6. Clinical Significance

    Mesenteric Lymphadenitis

    Mesenteric lymphadenitis is an inflammatory condition marked by the enlargement of mesenteric lymph nodes, typically due to:

    • Viral infections: e.g., adenovirus, enterovirus

    • Bacterial infections: e.g., Yersinia enterocolitica, Salmonella, Campylobacter

    It commonly presents with abdominal pain mimicking appendicitis, especially in children. Diagnosis is confirmed by imaging (ultrasound or CT).

    Lymphoma

    Primary or secondary involvement of mesenteric lymph nodes by non-Hodgkin lymphoma or Hodgkin lymphoma can result in:

    • Mass-like nodal enlargements ("mesenteric mass")

    • Constitutional symptoms (fever, night sweats, weight loss)

    Biopsy and histopathological analysis are essential for diagnosis.

    Metastatic Cancer

    Mesenteric nodes may harbor metastases from:

    • Small intestine and colon cancer

    • Pancreatic cancer (via shared drainage pathways)

    • Gastrointestinal stromal tumors (GISTs)

    Involvement can affect surgical staging and prognosis.

    Inflammatory Bowel Disease (IBD)

    In Crohn’s disease, mesenteric lymph nodes are frequently enlarged and may exhibit:

    • Granulomatous inflammation

    • Lymphoid hyperplasia

    Persistent mesenteric lymphadenopathy may help differentiate Crohn’s disease from ulcerative colitis.

    Imaging and Diagnosis

    Mesenteric lymph nodes are visualized using:

    • Ultrasound: First-line for children or suspected infection

    • CT scan: Best for detailed assessment of number, size, and distribution of nodes

    • PET-CT: Used in cancer staging to identify metabolically active lymphadenopathy

    Normal nodes are usually small (<5 mm short axis), oval, and non-clustered. Abnormal nodes may be round, large, clustered, or necrotic.

    Did you know? The spleen, located on the left side of the abdomen, filters blood and removes old or damaged red blood cells.