The role of the lymph nodes under the chin is mainly to participate in the immune response, help the return of fluids, and barrier function. 1. Involved in immune response: lymph nodes under the chin are involved in a variety of immune responses of the body, with white blood cells and other components of the body’s defense system. 2. Helping fluid return: blood passes through the arterial and venous system to all parts of the body, and a small portion of the blood can enter the lymphatic vessels to form lymph, and the lymph nodes under the chin can help the blood in the head to return to the superior vena cava. 3. Barrier function: Lymph nodes can intercept and remove bacteria and toxins that enter the lymph nodes, preventing them from spreading further and protecting the body. For more information on the role of the lymph nodes under the chin, please refer to your specialist textbook or consult your specialist.