Lymph Nodes

Lymph nodes perform essential roles in immune surveillance, fluid regulation, and detoxification:

• Filter Lymph Fluid: Traps bacteria, viruses, and debris
• Immune Cell Activation: Houses lymphocytes (T cells and B cells) that respond to pathogens
• Transport of Immune Signals: Facilitates communication between tissues and immune system
• Fluid Balance Support: Helps return excess interstitial fluid to the bloodstream
• Fat Absorption: Supports the transport of dietary fats from the intestines (via lacteals)

Key Takeaway

Lymph nodes are critical immune hubs, filtering harmful substances, activating immune responses, and maintaining fluid balance throughout the body.

Basic Structure

• Small, bean-shaped organs ranging from 0.1–2 cm, connected by lymphatic vessels
• Encased in a fibrous capsule and divided internally into compartments

Major Regions & Groups

• Cervical Nodes: Neck region
• Axillary Nodes: Armpits
• Inguinal Nodes: Groin
• Mediastinal Nodes: Chest
• Mesenteric Nodes: Abdomen
• Popliteal Nodes: Behind the knees

Protective Features

• Surrounded by capsule and connective tissue, protecting lymphocytes and filtration structures
• Internal sinuses allow lymph to flow while trapping pathogens and debris

Blood Supply & Nerves

• Supplied by small arteries and veins that nourish the node
• Connected to lymphatic vessels transporting lymph to and from tissues
• Innervation supports immune signaling and lymph flow

Key Takeaway

The strategic placement and structure of lymph nodes allow them to filter lymph efficiently, house immune cells, and respond rapidly to threats, forming an essential line of defense in the body.

• The body contains approximately 500–700 lymph nodes.
• Nodes can swell during infection as immune cells multiply.
• Lymph nodes play a role in cancer detection, as malignant cells may lodge and grow there.
• Lymph nodes filter 1–2 liters of lymph per day.
• Some nodes, like the mesenteric nodes, help absorb fats from the digestive system.

• Lymphadenopathy: Swelling of lymph nodes, often due to infection or inflammation
• Lymphoma: Cancer of lymphocytes that can originate in nodes
• Metastatic Cancer: Cancer cells from other tissues can lodge in lymph nodes
• Lymphedema: Blockage in lymph flow causing fluid buildup and swelling
• Infections: Nodes can become tender or inflamed during viral or bacterial infections

• Swelling or Tenderness in Neck, Armpits, or Groin
• Chronic Fatigue or Weakness
• Frequent Infections
• Persistent Swelling in Limbs (possible lymphedema)
• Night Sweats or Fever
• Unexplained Weight Loss
• Slow Recovery from Illness

Source: Amoeba Sisters