What is the function of lymphoid nodules?
A to help defend against infection where they are found
B to produce lymph
C to filter the blood for foreign matter
D to mature into larger lymph nodes
The correct answer and explanation is:
The correct answer is A: to help defend against infection where they are found.
Lymphoid nodules are clusters of lymphatic tissue found throughout the body, especially in areas such as the mucous membranes of the respiratory, gastrointestinal, and urogenital tracts. These nodules play a crucial role in the immune system by acting as sites for immune cell activation and providing defense against pathogens.
The main function of lymphoid nodules is to provide a localized area where immune cells, particularly lymphocytes (like B cells and T cells), can interact with antigens from pathogens that enter the body. The nodules contain specialized structures, including follicles, where B cells are primarily located. When an antigen, such as a virus or bacteria, is detected, the lymphocytes can respond by producing antibodies or initiating an immune response to neutralize or destroy the pathogen.
Lymphoid nodules are located in areas that are at higher risk of encountering pathogens, such as the tonsils, appendix, Peyer’s patches in the intestines, and mucosa-associated lymphoid tissues (MALT). These locations allow the body to detect and respond to infections at the sites where pathogens are most likely to enter.
While lymphoid nodules do not produce lymph (which is the role of the lymph nodes), they do interact with the lymphatic system. They help to filter pathogens out of the lymph fluid before it is returned to the bloodstream. However, their primary role is immunological defense rather than filtration of foreign matter from the blood, which is done by the spleen and lymph nodes. Lymphoid nodules do not mature into larger lymph nodes but instead serve as specialized areas of immune surveillance.