What are lymph nodes?

Lymph nodes are indeed small, bean-shaped structures that play a crucial role in the lymphatic and immune systems. Positioned throughout the body, they serve as filters for lymph fluid, which is a clear fluid that circulates within the lymphatic system. As lymph passes through the nodes, it is filtered of foreign particles, pathogens, and cancer cells, effectively playing a vital role in the body’s defense mechanisms.

Moreover, lymph nodes are a key location for the activation and proliferation of immune cells, particularly lymphocytes, which are essential in mounting an immune response. When the body detects infection or disease, lymph nodes can become swollen as they produce more immune cells to combat the threat. This function is critical for maintaining overall health and responding to infections.

The other options do not relate to the function or structure of lymph nodes. Muscle groups are unrelated to the immune response, organs producing red blood cells pertain to the hematopoietic system, and glands regulating hormone secretion are associated with the endocrine system—highlighting the unique and specialized role that lymph nodes play within the immune system.