Small organs that are part of the lymphatic system. They act in the defense of the body and produce antibodies. When enlarged, they are popularly called “inguas”. Among laypeople, the most well-known locations of lymph nodes are the neck, armpits, and groin. However, there are also lymph nodes in several other locations, such as above the collarbones, in the mediastinum, in the abdomen and in the pelvis.