The adenoids are a mass of lymphatic tissue located at the back of the nasal cavity, playing a crucial role in the immune system. They help trap and filter out pathogens, such as bacteria and viruses, that enter the body through the nose and mouth. Additionally, adenoids produce antibodies to help fight infections, particularly in young children, as they are more active during early childhood when the immune system is still developing. However, enlarged adenoids can lead to breathing difficulties, sleep apnea, and recurrent ear infections.