Organ
Lymph node
Organized immune tissue along a lymphatic route
High-yield
B-cell follicles occupy the outer cortex. T cells predominate in the deeper paracortex, and plasma cells occur in medullary cords.
Overview
A lymph node brings tissue-derived lymph into contact with organized populations of immune cells. Incoming channels feed sinuses beneath its capsule; lymph then passes through the node toward outgoing vessels at the hilum.
Reference facts
- Location
- Groups occur along lymphatic routes in the neck, axillae, groins and body cavities
- Parts
- Connective-tissue capsule and trabeculae; cortical follicles and paracortex; medullary cords and communicating sinuses
- Blood supply
- Blood vessels reach the hilum; specialized high endothelial venules allow many circulating lymphocytes to enter the tissue
- Venous/Lymphatic drainage
- Afferent vessels enter across the outer surface; efferent vessels leave at the hilum after lymph has traversed the sinuses
- Function
- Samples lymph, retains particulate material and supports antigen recognition and lymphocyte activation
Clinical correlation
Tenderness, firmness and mobility help guide assessment, but none alone establishes the cause of an enlarged node. Infection, inflammation and malignancy can produce overlapping examination findings.
Frequently asked questions
Where is the lymph node located?
The lymph node lies groups occur along lymphatic routes in the neck, axillae, groins and body cavities.
What does the lymph node do?
Samples lymph, retains particulate material and supports antigen recognition and lymphocyte activation.
What are the parts of the lymph node?
Connective-tissue capsule and trabeculae; cortical follicles and paracortex; medullary cords and communicating sinuses.
What is the blood supply of the lymph node?
Blood vessels reach the hilum; specialized high endothelial venules allow many circulating lymphocytes to enter the tissue.