Axillary lymph nodes are small, bean-shaped structures located in the armpit area. They are part of the lymphatic system, which helps the body fight infections and diseases. These nodes filter lymph fluid, trapping bacteria, viruses, and other harmful substances. There are typically 20 to 30 axillary lymph nodes on each side of the body. They play a crucial role in the immune response and are often examined during medical evaluations, especially in cases of breast cancer, to determine if cancer has spread beyond the original tumor site.