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    Related Topics

    From Lymphatic System

    Apical Axillary Nodes
    Located at the apex of the axilla.
    Central Axillary Nodes
    Located centrally in the armpit.
    Lateral Axillary Nodes
    Located along the humerus in the axilla.
    Supraclavicular Lymph Nodes
    Located above the clavicle; key in thoracic drainage.
    Tracheobronchial Nodes
    Drain lungs and bronchi.
    Mastoid Lymph Nodes
    Drain the posterior scalp and ear.
    Submental Lymph Nodes
    Drain the floor of the mouth and central lower lip.
    Bronchomediastinal Trunk
    Drains lymph from thoracic organs.
    Subscapular Axillary Nodes
    Located along the posterior chest wall.
    Palatine Tonsils
    Located on each side of the oropharynx.
    Para-aortic Lymph Nodes
    Drain abdominal viscera and lower limbs.
    Deep Cervical Lymph Nodes
    Located along internal jugular vein; receive lymph from head and neck.
    Superficial Cervical Lymph Nodes
    Drain superficial structures of the head and neck.
    Popliteal Lymph Nodes
    Drain the foot and leg.
    Lymph Nodes
    Small structures that filter lymph and store immune cells.
    Pharyngeal Tonsil
    Located in the nasopharynx (adenoids).
    Lymphatic Capillaries
    Initial lymphatic vessels that collect interstitial fluid.
    Occipital Lymph Nodes
    Drain the back of the scalp.
    Intestinal Trunk
    Drains lymph from the intestines.
    Inguinal Lymph Nodes
    Drain the lower limbs and external genitalia.
    Subclavian Trunk
    Drains lymph from the upper limbs.
    Thymus
    Primary lymphoid organ for T-cell maturation.
    Paratracheal Nodes
    Located lateral to the trachea.
    Anterior Mediastinal Nodes
    Drain anterior thoracic structures.
    SALT
    Skin-associated lymphoid tissue.

    Submandibular Lymph Nodes

    Reviewed by our medical team

    Drain the face, mouth, and pharynx.

    1. Overview

    The submandibular lymph nodes are a group of important lymph nodes located beneath the jaw, primarily responsible for draining lymph from the face, oral cavity, and anterior nasal structures. They are an essential component of the cervical lymphatic chain, serving both as a first-line filter for local infections and as a communication point with deeper lymphatic systems. Clinically, they are often examined for signs of infection or malignancy in the head and neck region.

    2. Location

    The submandibular lymph nodes are situated beneath the body of the mandible, within the submandibular triangle — an area bordered by the anterior and posterior bellies of the digastric muscle and the inferior margin of the mandible. These nodes lie superficial to the submandibular gland but may also be embedded within it. They are often found near the facial artery and vein as they curve around the mandible.

    3. Structure

    Each submandibular lymph node is a small, oval or bean-shaped organ encapsulated by connective tissue. Internally, it has a cortex containing lymphoid follicles (mainly B cells), a paracortex rich in T cells, and a medulla filled with plasma cells and macrophages. Lymph enters via afferent vessels, filters through the sinusoids, and exits via efferent vessels that drain into the deep cervical lymph nodes, particularly the jugulodigastric node.

    The group generally consists of 3–6 lymph nodes that are anatomically close to one another but serve distinct drainage areas of the face and mouth.

    4. Function

    The submandibular lymph nodes serve the following primary functions:

    • Lymph filtration: They filter lymph from key regions of the head and neck including the cheeks, upper lip, lateral parts of the lower lip, anterior nasal cavity, and much of the oral cavity including the floor of the mouth, tongue (except the tip), and gums.

    • Immune defense: They serve as immunological checkpoints where antigen-presenting cells activate lymphocytes to respond to pathogens or abnormal cells.

    • Lymph relay station: They pass filtered lymph to the deep cervical nodes, continuing the immune processing chain.

    5. Physiological Role(s)

    Physiologically, submandibular lymph nodes contribute to regional immune surveillance and fluid balance:

    • Detection of local infections: These nodes detect infections in oral and nasal structures and initiate local immune responses, including lymphocyte proliferation and cytokine release.

    • Monitoring antigenic content: By processing lymph from mucosal surfaces of the mouth and nose, they help the immune system respond to ingested or inhaled pathogens.

    • Response to inflammation or trauma: In conditions like dental infections, gingivitis, or facial wounds, these nodes often become reactive and swollen, reflecting their role in acute immune response.

    Because they drain regions constantly exposed to external microbes (e.g., oral flora), they are physiologically active even in healthy individuals.

    6. Clinical Significance

    Lymphadenopathy

    Submandibular lymph node enlargement (lymphadenopathy) is a common clinical sign and may be due to:

    • Dental infections: Conditions like periodontitis, periapical abscesses, or infected mandibular teeth.

    • Oral cavity infections: Including tonsillitis, pharyngitis, stomatitis, or tongue lesions.

    • Upper respiratory tract infections: Including viral illnesses such as mononucleosis or influenza.

    • Skin infections: Of the lower face or chin.

    Nodes are typically tender, soft, and mobile in infections, whereas malignancies may present as firm, non-tender, and fixed masses.

    Malignancy

    Submandibular nodes can be involved in metastatic spread from cancers of the oral cavity, tongue, floor of mouth, cheek, and salivary glands. Notably:

    • Squamous cell carcinoma of the oral cavity may first spread to these nodes.

    • Lymphomas may also present with painless enlargement of submandibular lymph nodes.

    Diagnostic Considerations

    • Palpation: Submandibular lymph nodes are routinely examined during physical assessment of the neck. Swollen nodes are evaluated for size, consistency, mobility, and tenderness.

    • Ultrasound and Fine Needle Aspiration (FNA): Used for deeper assessment or biopsy in case of persistent or suspicious swelling.

    Postoperative and Radiological Notes

    In head and neck surgeries, especially those involving the submandibular gland or mandible, care must be taken to preserve or assess the involvement of submandibular nodes. They may also be removed during selective neck dissections for oral cancer treatment.

    Did you know? The tonsils, which are part of the lymphatic system, help trap pathogens that enter through the mouth or nose.