Secondary Lymphoid Organs and Their Functions
Secondary lymphoid organs also known as peripheral lymphoid organs are the sites of proliferation and differentiation of B and T-lymphocytes. undergo proliferation and differentiation. These lymphoid organs include the following:
Lymph Nodes
These are small bean-shaped specialized lymphoid tissues through which the lymph flows its way back to the blood. The selection of B lymphocytes occurs in the germinal center of these lymph nodes. They also filter the lymph and prevent foreign particles or germs from entering the bloodstream.
Spleen
This bean-shaped organ is the largest of all lymphoid organs located in the left upper abdomen under the diaphragm. It removes antibody-coated bacteria and damaged blood cells. It is also involved in the synthesis of antibodies.
Tonsils
They are a pair of soft tissue masses located at the back of the throat near the palate region. Palatine tonsils, adenoids, and lingual tonsils are together known as Waldeyer’s rings. They protect the body by filtering bacteria and viruses from blood cells.
Peyer’s Patches
These are small clusters of lymphoid nodules located throughout the mucus membrane of the small intestine, especially along the ileum. They are part of gut-associated lymphoid tissue (GALT). They play an important role in controlling the growth of pathogenic bacteria in the intestines.
Mucosal-Associated Lymphoid Tissues (MALT)
MALT is an aggregate of many lymphoid tissues found in the mucosal lining of respiratory, digestive, and urinogenital tracts and also in the submucosal membranes of salivary glands, thyroid, breast, nasopharynx, lungs, eyes, and skin. They are the center of lymphocyte production.
What Are Lymphoid Organs?
Lymphoid organs are part of the lymphatic system that performs many immunological functions. The lymphatic system is comprised of organs, vessels, lymph nodes, and lymph. Lymphoid organs are mainly of two types-primary and secondary lymphoid organs. The primary lymphoid organs or the central lymphoid organs such as bone marrow and thymus are the site of the maturation of lymphocytes. In contrast, the secondary lymphoid organs, also known as peripheral lymphoid organs like spleen, lymph node, etc. are associated with the initiation of adaptive immune response. In this article, we will explore lymphoid organs, types, and differences between primary and secondary lymphoid organs.
Table of Content
- What are Lymphoid Organs?
- Types of Lymphoid Organs
- Primary Lymphoid Organs and their Functions
- Secondary Lymphoid Organs and their Functions
- Tertiary Lymphoid Organs and their Functions
- Internal and External Lymphoid Organs
- Differences Between Primary and Secondary Lymphoid Organs
- What is the Function of the Lymphoid Organs?
- Diseases Associated with Lymphoid Organs