01 / Location & anatomical relationships
Along lymph vessels, including in the neck, armpits and groin.
02 / Structure & organization
Lymph enters through afferent vessels, passes through sinuses and leaves through efferent vessels near the hilum. Cortical follicles, paracortical regions and medullary areas organize different immune-cell populations.
03 / Function
They filter lymph fluid and contain immune cells.
04 / Mechanism
Lymph fluid passes through internal spaces containing immune cells. These cells can recognize foreign material and help start a defense response. Many nodes work together as part of the body's immune network.
Working together: lymphatic & immune systems
Lymph vessels collect extra fluid from tissues. Lymph nodes filter that fluid, and immune cells help recognize and respond to germs.
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Connect structure with function
Nodes are meeting sites for antigens and immune cells, not simple mechanical strainers. Their structure supports recognition, activation and coordinated immune responses.
Check your understanding
Locate the lymph nodes in relation to its neighbors. Explain how the structural features described above support its function, then distinguish it from a nearby structure with a different role.
Keep learning
Continue with OpenStax Anatomy and Physiology for system-level study. This atlas is educational and has not undergone independent medical peer review.