Lymph nodes

Definition

Lymph nodes are small, bean-shaped structures that are part of the lymphatic system. They filter lymph fluid and house immune cells that help fight infection and disease.

5 Must Know Facts For Your Next Test

1. Lymph nodes contain high concentrations of T lymphocytes and B lymphocytes, crucial for adaptive immunity.
2. They act as filters for foreign particles and pathogens, preventing them from entering the bloodstream.
3. Swollen lymph nodes often indicate an active immune response to infection or illness.
4. Lymph nodes are strategically located throughout the body, including in the neck, armpits, and groin.
5. The afferent lymphatic vessels bring unfiltered lymph into the node, while efferent vessels carry filtered lymph away.

Review Questions

• What types of immune cells are primarily found within lymph nodes?
• Why do lymph nodes swell during an infection?
• Explain the path of lymph fluid through a lymph node.

Related terms

T Lymphocytes: A type of white blood cell involved in cellular immunity that matures in the thymus.

B Lymphocytes: A type of white blood cell responsible for producing antibodies against antigens.

Lymphatic System: A network of tissues and organs that help rid the body of toxins and waste through a clear fluid called lymph.